Diff Dilemna! Need opinions!

[mshred]

hey guys,
ive gotten myself into quite the pickle...after taking my car to the track and experiencing severe wheelhop and still running it (i know im an idiot...lets not go there) i have ran into more problems...the car only ran a 13.6 with a t5 5 speed, was planning on upgrading to a tko or 833 and building a 12 sec or faster motor for it next year (who knows if that will happen now)

the car has a 489 8-3/4 with 30 spline mosers and stock suregrip...well, the side with the wheelhop (driver side) axle has twisted splines...also, i found chunks of teeth in the rear end...the ring and pinion are fine, which leads me to believe it came from the spider gears (havent looked into yet, got late and have to work tommorow, but will check tommorow)
Im stuck as to what i should do...my car only runs 13's (with a stickshift albeit) and ive already twisted a tranny yolk (1350 too!) and twisted an axle...moser doesnt offer any warranty on these axles, so i have a few options

#1-try and find spider gears and try to get moser to send me one replacement axle...depending on how much this costs though, option two may be better
#2- get an axle and spool kit in 35 spline count, stuff it back into the 8-3/4 and continue to drive it (car is a street car though primarily, so not so sure how well the spool would fare...car gets LOTS of miles)
#3- forget the 8-3/4 altogether, cut the losses, and try and find a used dana in a-body length with what im looking for, or try to find a place that sells a complete D60 for 1200 bucks and under (i cant spend anymore...im broke)

What do you guys think i should do? the car is staying a stickshift forever, and my plans are only to go faster with it...it is also a street car before anything else
im scared though that whatever i do if i get wheelhop again i may break stuff again (was thinking of sticking twisted axles back in and correcting wheelhop first in the suspension, and then fixing the diff problems)
anyways, im open to anything right now...please share what you would do

 

[LXguy]

Something else is f'ed up someplace. No way you should be doing that kind of damage to an 8.75 unless you've got a POS Auburn diffy in there.

Was the adjuster removed?

Dont run a spool on the street. It sucks.

 

[mshred]

Something else is f'ed up someplace. No way you should be doing that kind of damage to an 8.75 unless you've got a POS Auburn diffy in there.

Was the adjuster removed?

Dont run a spool on the street. It sucks.

well like i said, i had severe wheelhop, so i know thats what killed it...the wheel hop was on the driver side, and sure enough it is the driver side axle that is twisted...i know the cause of the problem, its just a matter of dealing with it now

how bad are spools on the street? i know its really a matter of opinion, but my car see lots of street miles, and doesnt have power steering either

 

[DartOS]

If it's mainly a street car, don't go with a full spool. Y'all get a bunch more snow and rain than we get in west Texas. When it does rain here the car stays in the barn. Way too dangerous on slick roads. Try a Detroit Locker. I believe you can get a 30 spline for around $590.

 

[LXguy]

Wheelhop isn't caused by the diff. If you put a spool in, it won't fix that problem.

Everything is an opinion, but mine is that its not worth it to run a spool. There are plenty of differentials that should be able to handle what a street car is going to dish out.

In addition to the hazards DartOS mentioned, the lack of slip puts a ton load on everything in the axle.

Try and push a spool car with the wheels turned even a little bit sometime.

 

[highwaystar]

what kind of suspension are you running? What is the pinion angle on your current set-up? I've never had a wheel hop problem in any of my Mopars. Something in the set-up is wrong.

 

[684mulas]

Based on your last thread, I realize you might not want to hear this but, I would not be surprised if the problem started with trying to launch your car with big tires and the 6 cyl leaf springs. Most of these problems usually begin with the simple stuff.

You obviously have some repairs to do but you should really consider getting the 002-003 superstock springs, long shocks and correct the pinion angle (in that order) or you may end up breaking things again. You should easily be able to run in the 12s without breaking things with a manual trans as long as everything is in good working order and set up correctly.

 

[mshred]

for those that already know, i know what the wheelhop was caused by...it was my pinion angle (another thread i had made was about that)...i believe the pinion angle mixed with possibly shocks not being long enough was the cause of the hop...because i kept launching with the hop, this was the result...its not the diffs fault, it was mine...the driver side hopped and its the driver side axle and side gear that had the most damage

as far as spools and suregrips go, id like to keep a stock style suregrip in the car until it wont last anymore, but im not sure how fast i can go in a stick car with one before grenading it...the car may not be fast now, but plans are for more power in the future, and id like to spend my money once and have it last...for sure no locker will go into my car...have heard too many stories of stick cars unloading during a shift and going straight into a wall because the locker unlocked...not something i trust, and this car is never going slushbox...way too boring...that being said, what else besides lockers and spools are out there that work well and are rebuildable?

like i said, i know for a fact my pinion angle is what caused the hop (3 degrees nose up...i know dont even ask)...ive reset it to about 5 degrees nose down, but i havent tested it out yet since i have the carrier apart (luckily i had a spare 489 cone style suregrip in the garage that i used to fix the problem) but im looking for a more long term solution as i still have a twisted axle

and in regards to the 6 cyl springs and my wheelhop, like i already said in the other thread im going to do things one step at a time...have seen plenty of guys run 1.60 60ft. times with stock 6cyl leafs, and i have a leaf added to mine...if i still got hop, i will go to the shocks...and if still after that will i only then go to fixing my springs...cheapest and more likely the cause first

havent tested out the new pinion angle yet, so we will see what that nets me
still interested in your opinions about what i should do for rearend choice...i already know the cause of my wheelhop no need for this thread to go off topic about how to fix that (another thread)

thanks guys!
Matthew

 

[LXguy]

Well if you want to go crazy...

Detroit Truetrac (Its not a locker)

I'd think a clutch type Mopar diffy would be fine though. Lots of Ford guys going 10s on 31 spline stock Ford diffs (with C-clips no less). Mopar unit *looks* beefier, and is rebuildable

The trick is that everything else has to be right. You say you only want to spend money once, then you say you're going to wait to tear things up (again) before swapping to the good stuff. Shocks and springs are way cheaper than high dollar differentials.

If you don't wait to have terrible wheelhop you won't need an Ox diffierential.

My average 60 foot is 1.59 - 1.61 and I'm currently running a cone style Sure Grip.

 

[mshred]

Well if you want to go crazy...

Detroit Truetrac (Its not a locker)

I'd think a clutch type Mopar diffy would be fine though. Lots of Ford guys going 10s on 31 spline stock Ford diffs (with C-clips no less). Mopar unit *looks* beefier, and is rebuildable

The trick is that everything else has to be right. You say you only want to spend money once, then you say you're going to wait to tear things up (again) before swapping to the good stuff. Shocks and springs are way cheaper than high dollar differentials.

If you don't wait to have terrible wheelhop you won't need an Ox diffierential.

My average 60 foot is 1.59 - 1.61 and I'm currently running a cone style Sure Grip.

like i already said, im putting back in the bent axle and fixed the suregrip for free= no money....therefore the car is back on the road up and running, but id like to upgrade BEFORE i tear anything up...if i get wheelhop on my first test pass i know exactly what to do next...im not going to keep going at it...im just getting the car running again, not racing

suspension is getting sorted out before i buy new diff stuff...no point of buying brand new stuff to just break it again

 

[turbodart68]

Are you running a pinion snubber? I am asking because I run 6 cylinder springs with a leaf removed to get the car low. I run 4 degrees of negative pinion angle and the pinion snubber lightly touching the floor. I also used summit racing adjustable shocks with them set at 70/30. I have gone as fast as 1.48 in the 60 foot and have no problems with wheel hop. I think you are on the right track with the pinion angle, if it goes positive it will pogo and ruin diff parts at an alarming rate. A lot of people forget to set the pinion snubber properly. I also run a clutch type factory sure grip and have gone into the nines with my turbo Dart. I think that 10's should work with a stick car.

On another note I run a spool on the street and have had no problems with it, however it is tougher on tires. Of course it doesn't rain much nor snow ever.

 

[mshred]

Are you running a pinion snubber? I am asking because I run 6 cylinder springs with a leaf removed to get the car low. I run 4 degrees of negative pinion angle and the pinion snubber lightly touching the floor. I also used summit racing adjustable shocks with them set at 70/30. I have gone as fast as 1.48 in the 60 foot and have no problems with wheel hop. I think you are on the right track with the pinion angle, if it goes positive it will pogo and ruin diff parts at an alarming rate. A lot of people forget to set the pinion snubber properly. I also run a clutch type factory sure grip and have gone into the nines with my turbo Dart. I think that 10's should work with a stick car.

On another note I run a spool on the street and have had no problems with it, however it is tougher on tires. Of course it doesn't rain much nor snow ever.

thats slightly comforting information lol

like i said, i know that the pinion angle was the biggest factor in my wheelhop, and like an idiot launching with wheelhop killed my parts

id like to try and make an 8-3/4 live as long as possible, but i dont want to keep throwing money at it...another thing i have to account for is that stick cars put ALOT more stress on driveline parts than autos...id put a spool in before i put a locker, but id rather keep it suregrip for as long as i can

 

[CHEATHAM]

It dont take much to swap a diff for the spool to go racing for a day then swap back

 

[moper]

The damage was done by the hop, as you said. So in addition to fixing what broke, you have to fix the hop. Pinion angle is part of the problem. Put GOOD shocks on the rear. The best double adjustables you can afford. By repairing the rear and partially addressing the suspension you're asking to throw good money away IMO. As far as differentials for teh street... There's only one I use. The Detroit Tru Trac. You should not ever run a spool on the street. Some guys do with success, I never will condone it. First and foremost its the cheap *** way out of getting the one up side of the limited slip. However it also stresses the axles (which is why aftermarket ones are mandatory in all racing bodies) and should it or an axle break, regardless of full throttle or part throttle, the car will make an immediate turn in the direction of the broken axle. So take a sweeping highway on ramp where you get on the throttle in 2nd, just as you upshift to 3rd the end shears off the axle in the inside of the curve... And you and the car go abruptly off the road. Not for me, an not in any car I build/work on. I'd prefer you not even be in the road with me, it is that dangerous.
You don't need a dana. What I see is you need a good rear suspension and you're worried about tossing good money away but leaving part of the problem in place. Shocks are a recurring problem on A bodies. It's a cheap and easy fix. MP had shock extenders in the 60s so this is nothing special to your car.

 

[LXguy]

I can recommend the Ranchos that Calvert sells for rear shocks. Or at least they work decently awesome on my car. Cheap too.

Another big factor in getting rear end stuff (and transmissions) to live is choosing the right clutch. And that T-5 is going to need all the help it can get.

I don't know what the flywheel you're using calls for, but if its compatible, I highly recommend the clutches that these guys sell.

http://www.promotionpowertrain.com/NEW_FORD_CLUTCH_PAGE.html

If that pressure plate won't bolt up, maybe they could point you to one that will. These clutches feel like something out of a Honda Civic (with a cable clutch setup even) and I've run 10 second quarter mile times with them.

Steve

 

[mshred]

The damage was done by the hop, as you said. So in addition to fixing what broke, you have to fix the hop. Pinion angle is part of the problem. Put GOOD shocks on the rear. The best double adjustables you can afford. By repairing the rear and partially addressing the suspension you're asking to throw good money away IMO. As far as differentials for teh street... There's only one I use. The Detroit Tru Trac. You should not ever run a spool on the street. Some guys do with success, I never will condone it. First and foremost its the cheap *** way out of getting the one up side of the limited slip. However it also stresses the axles (which is why aftermarket ones are mandatory in all racing bodies) and should it or an axle break, regardless of full throttle or part throttle, the car will make an immediate turn in the direction of the broken axle. So take a sweeping highway on ramp where you get on the throttle in 2nd, just as you upshift to 3rd the end shears off the axle in the inside of the curve... And you and the car go abruptly off the road. Not for me, an not in any car I build/work on. I'd prefer you not even be in the road with me, it is that dangerous.
You don't need a dana. What I see is you need a good rear suspension and you're worried about tossing good money away but leaving part of the problem in place. Shocks are a recurring problem on A bodies. It's a cheap and easy fix. MP had shock extenders in the 60s so this is nothing special to your car.

hey dave,

i understand the shock thing...like ive said, im doing everything one step at a time here...if i launch once and get hop, the shocks are being changed out...originally before i even took it to the track i had called calvert and inquired about their 90/10's and rancho 9000s for my car, but i never got around to ordering the stuff after the mess at the track...just been trying to fix that and get back up and running...im doing what i can as i can afford it, and im sure anyone can understand that reasoning

as far a dana goes, i agree that i shouldnt need one yet...just looking for opinions on all this...and the stuff you raise about a spool brings up a good point..however, is the detroit true trac rebuildable?

 

[highwaystar]

I agree with Moper. I run a Detroit True-Trac, with a set of Strange SS axles (street and Strip) I have broken sh-t since putting them in, but it's not axles or posi. Like one fellow told me on a 4 spd sight, "super stock springs with adjustable snubbers have way to much axle wind-up and your going to break stuff". He told me to put the caltracs in and it will cut that way back. Automatics are alot different for all that are about to jump on me, defending there SS leaf spring set-ups. I ran low 11's on a 904 automatic for years on end with no rear suspension breakage. I have a streetable mid 12 second motor behind my 4 spd. now and have broke alot.

 

[Small Block]

Here ya go. I'm running a stock/6 spring under an Eaton TruTrac 3.91 gear behind a 400+ horse 440 with a 727. No issues at all. The Eaton is a gear drive sure grip. Pulls the same on both sides. They claim good to 600 horse. The axles are Yukons. Do it once with a TruTrac.
Small Block

 

[mshred]

I agree with Moper. I run a Detroit True-Trac, with a set of Strange SS axles (street and Strip) I have broken sh-t since putting them in, but it's not axles or posi. Like one fellow told me on a 4 spd sight, "super stock springs with adjustable snubbers have way to much axle wind-up and your going to break stuff". He told me to put the caltracs in and it will cut that way back. Automatics are alot different for all that are about to jump on me, defending there SS leaf spring set-ups. I ran low 11's on a 904 automatic for years on end with no rear suspension breakage. I have a streetable mid 12 second motor behind my 4 spd. now and have broke alot.

thanks for the info man! i called calvert last Friday and talked with them at length about their setup...he told me it obviously works best as a package...when i asked him about street driving the monos, he said most super stock spring guys like the ride better on the monos, and that they will ride fine on the street...i told him i put about 5k a year on the car and was worried they would wear and he said he would replace for free if that happened since he gurantees it wont..but this tru trac thing is something i have to look into

Here ya go. I'm running a stock/6 spring under an Eaton TruTrac 3.91 gear behind a 400+ horse 440 with a 727. No issues at all. The Eaton is a gear drive sure grip. Pulls the same on both sides. They claim good to 600 horse. The axles are Yukons. Do it once with a TruTrac.
Small Block

another tru tracker lol...question i have guys is are these tru trac units rebuildable, or are they like the auburn posi where once they break they are garbage? if so, i find that rather useless

 

[Small Block]

Rebuildable? No expert but a simple phone call to the right place will answer your question. They are all gears and do dissasemble so i'll lean toward yes as being my answer. I dont know of anyone that tore one up. I'm sure there are though.
Small Block

 

[684mulas]

I would make sure the flange on that twisted axle runs true before trying to launch that car again. The reason I keep chiming in and harping on the springs is because I've broken things automatics and stick.

Every time you dump that clutch, you are putting your driveline to the test. You will quickly find the weakest link. a couple of years back, I discovered a problem with my back U-joint. Of course the U-joint broke but so did my driveshaft bend, the casing on my original matching # trans, and the output shaft bent (see picture). The point here is that a $20 U-joint caused many hundreds in damage and many hours of work.

My 4-speed car runs low 12s easily with SS springs, good long Edelbrock shocks, correct pinion angle and drag radials (yea, heavy duty drive shaft and u-joints). It could go 1/2 sec faster with slicks but thats when stuff starts to break and I drive to and from the track want it to be reliable.

I don't want you to spend as much money as possible. Its just the opposite but it seems that you have your heart set on doing things a certain way and thats fine but you might break more things and spend a lot more money than necessary. A Caltrac system is exceptionally nice and will do the job but its probably more than you need. Serious my friend, check out that axle before trying to put power to it. If it has any wobble, things will break.

How about finding some smaller tires and put them on the back to test all of this out so there is less stress on the system? If you were closer, I have an extra set of new xhd springs that I would be happy to lend you so you can experiment. Is there any members close to you who can lend you some SS or XHD springs? More importantly now, can someone lend you an axle?

 

[LXguy]

thanks for the info man! i called calvert last Friday and talked with them at length about their setup...he told me it obviously works best as a package...when i asked him about street driving the monos, he said most super stock spring guys like the ride better on the monos, and that they will ride fine on the street...

I run my monoleafs on the street. The ride is a bit stiff, but not horrible (part of that might be the shocks too). However, the solid bushings do transmit a good bit of gear/tire/road noise into the car. If you're looking to put a lot of miles on the car it could get tiresome. I literally thought there was something wrong with my differential when I took it for the first mono leaf test drive. If you put sound deadening under the rear seat it might make a little difference. Maybe.

That said, they work.

another tru tracker lol...question i have guys is are these tru trac units rebuildable, or are they like the auburn posi where once they break they are garbage? if so, i find that rather useless

Detroit says they want you to send it back if repairs are needed. However, you'd have to really be screwing up to break one. I know a racer with a low 10 / high 9 second car (yes its a stick) that runs one and has no issues. Well, no differential issues.

Also know a couple of 4 wheel guys that swear by them.

 

[moper]

As was said, they rate them at 600hp but I've never heard of soemone breaking one. I've got a few behind real 500hp engines with no troubles. They are a gear type... I've never had one that needed service so honestly I don't know if you rebuild them...lol. I would still put shocks in it but that's me. I also ran the solid bushings on my Cuda years ago. I replaced them with poly and it was 100% better. The solid bushings are not fun.

 

[mshred]

I would make sure the flange on that twisted axle runs true before trying to launch that car again. The reason I keep chiming in and harping on the springs is because I've broken things automatics and stick.

Every time you dump that clutch, you are putting your driveline to the test. You will quickly find the weakest link. a couple of years back, I discovered a problem with my back U-joint. Of course the U-joint broke but so did my driveshaft bend, the casing on my original matching # trans, and the output shaft bent (see picture). The point here is that a $20 U-joint caused many hundreds in damage and many hours of work.

My 4-speed car runs low 12s easily with SS springs, good long Edelbrock shocks, correct pinion angle and drag radials (yea, heavy duty drive shaft and u-joints). It could go 1/2 sec faster with slicks but thats when stuff starts to break and I drive to and from the track want it to be reliable.

I don't want you to spend as much money as possible. Its just the opposite but it seems that you have your heart set on doing things a certain way and thats fine but you might break more things and spend a lot more money than necessary. A Caltrac system is exceptionally nice and will do the job but its probably more than you need. Serious my friend, check out that axle before trying to put power to it. If it has any wobble, things will break.

How about finding some smaller tires and put them on the back to test all of this out so there is less stress on the system? If you were closer, I have an extra set of new xhd springs that I would be happy to lend you so you can experiment. Is there any members close to you who can lend you some SS or XHD springs? More importantly now, can someone lend you an axle?

I understand all of that...but one launch in an abondoned area i dont think will spell demise for my stuff...its just one, just to see if its still there, and if it is, im out of it and takin her home to order new parts....like i said already one thing at a time

i have 1350 u joints, a 3.5" d-shaft, and it has been freshly rebalanced so im good there (thats what i had even before the disaster, but got it all checked out to be safe)...as far as tires go, even though mine are wide, they spin constantly, so i should be okay in terms of not putting alot of stress...they are just a wide street tire

I understand everyone is trying to help, but i want the car on the ground to test and then move from there..i dont think one launch will kill it, and if it does, well then you can all i say i told you so lol

but like i said, one bit of hop and im jumping on the suggestions and putting them into action

 

[mshred]

moper and LXguy, those tru tracs seem like something definatly worth looking into...i will check them out

as far as the caltracs go, im not fully decided yet if i want to go with them...some say they ride ok on the street others no...everyone has different opinions of whats streetable so ultimatly its up to me...but thanks for sharing your experience, gives me a better idea of what to expect