explorer 8.8 in an a-body: experience needed

[pishta]

Bit of advice... If you're going to run slicks box the spring perches so they don't collapse under acceleration. I found out the hard way ;) Welding the axle tubes to the Pumpkin makes it stronger too. Otherwise the pumpkin can spin out the rosette welds in the axle tubes. Both things only happen under extreme load.

The axle tubes are steel, the pumpkin is iron.....get some help on that bi-metal weld as iron is a bear to weld on if you dont know what you are doing. Make yourself a "bottom" brace that goes under the pumpkin and ties the tubes together. Or better, bolt it across a cast AL rear "girdle" 8.8 cover, thatll lock the axles.

 

[/6 Matt]

Interesting dialog. I am looking to do the same with my '65 Valiant. The cost of 8.75" Sure Grip from a B-body is painful. If I have less than 400hp I would think this could be an affordable solution to replace my weak 7.25" stock rear end. I wish this thread gave more specific "how to" and less "you can't do that"!

This thread is toast, already eaten by the people who want to spend all day telling you not to do it.

Here's is a great thread documenting a complete swap:http://www.forabodiesonly.com/mopar/showthread.php?t=89918

It pisses me off when someone around here asks a question and everybody jumps in on there opinions instead of answering the question.

The op asked a question. Ten people said that he should do an 8.8, ten people said fix the 8-3/4". Two people are acting like jack@sses at 2am and the op still hasn't had his answer. Time and time again I've been on the side of the fence the op is on and I'd just abandon the thread, go it alone, and screw stuff up because I never got the advice I needed.

 

[Idaho]

I understand the role of the proportioning valve. What is a residual valve?

Edit: reading this now...

http://www.thebrakeman.com/valvetechi

Based on the article above, those of us putting an 8.8 with discs where there were drums should be making sure we have no residual valve. I've read everything I've seen on the 8.8 swap here and not seen this discussed.

 

[/6 Matt]

Based on the article above, those of us putting an 8.8 with discs where there were drums should be making sure we have no residual valve. I've read everything I've seen on the 8.8 swap here and not seen this discussed.

I agree, because if I remember, the residual pressure check valve is needed to keep aout 8-10psi on drums to prevent dirt and debries from entering the brake system through the wheel cylinder.

I was once considering an 8.8 swap and retaining my front drums till I can afford a BBP disc swap.

To do that, I would need a an inline proporting valve (adjustable) to control brake bias, as well as an inline metering valve to keep the discs from activating untill sufficent pressure (60-80psi) is on the drums to overcome to springs to prevent the rear wheels from locking up under hard braking. Lastly the MC would have to be changed because on vehicles with 4-wheel drums, the residual pressure check valve is built in to the master cylinder and the residual pressure on the rear circuit would cause the brakes to drag back there.

Moreover a vehicle considering this swap with front disc brakes, adding the 8.8 with discs to the rear would eliminate the need for a residual pressure check valve as well as a metering valve. The only thing required would be the adjustable proportioning valves on both circuits.

 

[/6 Matt]

Time and time again I've been on the side of the fence the op is on and I'd just abandon the thread, go it alone, and screw stuff up because I never got the advice I needed.

Case in point guys, the op hasn't been on this thread since 10-18-2010. He abandoned the thread while everyone else bickered there point to the practicality of the swap. His question was never answered. Hopefully whatever he did, worked out for him in the end.

 

[pupjoint]

Running 8.8 in my duster, 373 gears, disc brake set up had no problems. Did not see where it was mentioned that you can buy a conversion u-joint. That is the way I went.
And I will say for 150.00 I would do it again.

 

[fishy68]

Case in point guys, the op hasn't been on this thread since 10-18-2010. He abandoned the thread while everyone else bickered there point to the practicality of the swap. His question was never answered. Hopefully whatever he did, worked out for him in the end.

Be bitter if you like Matt but I've seen it time and time again where someone asked a question and no comments on the contrary happened and the OP never came back to say any more. As for the comments on why not to do a conversion, some of us have numerous yrs. of experience with rear ends and know most of the ends and outs and when we see something that we feel is non productive (lets face it, guys with no experience will sometimes swallow BS) we feel it's good to offer a counter point. That's exactly what I did when I posted my comments.

 

[Idaho]

I'm wondering if there's folks wearing out their brakes quickly due to having residual valves in their systems. Maybe its not being noticed due to most cars not seeing a lot of miles. There is the concern of them heating up during highway driving as well.

 

[/6 Matt]

Be bitter if you like Matt but I've seen it time and time again where someone asked a question and no comments on the contrary happened and the OP never came back to say any more. As for the comments on why not to do a conversion, some of us have numerous yrs. of experience with rear ends and know most of the ends and outs and when we see something that we feel is non productive (lets face it, guys with no experience will sometimes swallow BS) we feel it's good to offer a counter point. That's exactly what I did when I posted my comments.

I am bitter and I do see the validity of your point. I'll leave for awhile and cool down. If I don't come back to this thread, just know I do see the perspective from your side of the fence.

PS: I think somebody pissed in my cornflakes today, my bad guys.ops:

 

[Hersbird]

Fishy I have looked and looked for a a body sure grip with good ratios and not only have I not come across one, the bad ratios non sure grip ones seem to go for $300. I'd say a ready to go 8 1/4 3.55 sure grip would be more like $600 and it's not as strong as the explorer 8.8.

If the brakes are such a concern they did make drum explorer 8.8s in the 95 and older, less expensive too. You can probably buy a whole 94-95 explorer with a blown trans for less then $500, take the rear end and sell the other parts for your $500 back then scrap the body for another $100. While I believe its possible to grossly warp the tubes welding spring perches, I'd say with the basics of patience you would be fine.

I'm all for keeping a mopar a mopar but there is no way the most expensive part of my Barracuda is going to be the rear end!

 

[pishta]

I dont think they used risidual valves for years, that is old tech, modern drums and any repair parts include a new style piston cup that doesnt need a few lbs to force the lip against the cylinder. Case in point. When was the last time you cracked the rear brake bleeder and had 10psi fluid shoot out, never? I cannot recall a time. I believe the 8.8 has small drum E brakes in the rotor hubs. I dont have the one I did as the guy had the brakes off when I cut it. 2 short axles, 3 inches off the long side tube and reweld, lay it up in there and mark for new perches. Get yourself a bolt on yoke for a 1350 U and then get a 1350 end on your driveshaft. Mustangs already have equal side shafts. adjustable prop valve and your set. Do it, or build another 8.75 SBP rear with 40 year old parts. The 8.8 will cost less than a set of 8.75 gears and bearings.....

 

[fishy68]

I am bitter and I do see the validity of your point. I'll leave for awhile and cool down. If I don't come back to this thread, just know I do see the perspective from your side of the fence.

PS: I think somebody pissed in my cornflakes today, my bad guys.ops:

I've been the same way today brother. Hate it when I'm in a mood like that. :banghead:

 

[fishy68]

Fishy I have looked and looked for a a body sure grip with good ratios and not only have I not come across one, the bad ratios non sure grip ones seem to go for $300. I'd say a ready to go 8 1/4 3.55 sure grip would be more like $600 and it's not as strong as the explorer 8.8.

If the brakes are such a concern they did make drum explorer 8.8s in the 95 and older, less expensive too. You can probably buy a whole 94-95 explorer with a blown trans for less then $500, take the rear end and sell the other parts for your $500 back then scrap the body for another $100. While I believe its possible to grossly warp the tubes welding spring perches, I'd say with the basics of patience you would be fine.

I'm all for keeping a mopar a mopar but there is no way the most expensive part of my Barracuda is going to be the rear end!

Have you checked the for sale section lately. Just saw one listed with a 3.55 sure grip for $200. A lot of it is being at the right place at the right time as you know. I'm rarely there, LOL

BTW: have you looked at Ranger rearends? My father-in-law has a 64 Rambler American and it has a 95 Ranger 8.8 in it and I measured it and it measured within 1/2" of what the 8-3/4 in my Cuda measures and is offset the same. Plus it's got the 5 on 4.5" bolt pattern. I don't know if it has been modified but it doesn't look like it was other than the Ranger mounting brackets were cut off and Mopar spring pads welded on. Oh yeah, the yoke is different so you'd need a yoke to connect it to a Mopar U-joint

 

[ab7fh]

The axle tubes are steel, the pumpkin is iron.....get some help on that bi-metal weld as iron is a bear to weld on if you dont know what you are doing. Make yourself a "bottom" brace that goes under the pumpkin and ties the tubes together. Or better, bolt it across a cast AL rear "girdle" 8.8 cover, thatll lock the axles.

I ran it for 13 years that way... Just swapped out the 8.8 for a RockJock 60 a couple months ago. On the 8.8 I ran a T/A aluminum cover with the bearing cap preload screws and it never had any problems. I was running an ARB airlocker in it and 36x12.5 tires on a 5000lb vehicle. Amazing how well the 8.8 held up to the abuse. A bottom brace isn't practical for the kind of fourwheeling I do. I need all the clearance I can get.

 

[Hersbird]

I read every classified posted here every day, Fishy I saw that one but I think you are talking about an Aspen rear. I might be able to find a good F body 8 1/4 that cheap but then you still have just as much work or more to get it to fit the A body as if using a 8.8. I KNOW there are a crap load of good explorer rears, right here, no shipping or spending $100 on gas to pick up. I have been looking and waiting for a ready to go 8 1/4 posi with 3.55 gears for a good 5 years now, never has one been posted (here or craigslist) close enough for me to get. I live an hour from Dr Diff so for the longest time I was just going to save and get one of his 8 3/4 setups, but now plan on doing the 8.8.

I had a buddy just call me with a ranger rear last week but he hasn't got back to me on exactly what it is. I think it's not an 8.8 but the smaller one they used, early to mid 90s. Even then the ranger 8.8 is not nearly as strong as the explorer 8.8. different spline count, different axle shaft thickness.

From what I see all the 8.8s weather in a ranger, mustang, or explorer use the same length short side axle and then use a different length long side to get the overall length. The mustang guys always pilfer the short side ranger axles to convert to 5 lug pattern.

I often wonder if those talking about weak 8.8s are talking about explorer 8.8s or if they have a mustang or ranger 8.8.

 

[fishy68]

I read every classified posted here every day, Fishy I saw that one but I think you are talking about an Aspen rear. I might be able to find a good F body 8 1/4 that cheap but then you still have just as much work or more to get it to fit the A body as if using a 8.8. I KNOW there are a crap load of good explorer rears, right here, no shipping or spending $100 on gas to pick up. I have been looking and waiting for a ready to go 8 1/4 posi with 3.55 gears for a good 5 years now, never has one been posted (here or craigslist) close enough for me to get. I live an hour from Dr Diff so for the longest time I was just going to save and get one of his 8 3/4 setups, but now plan on doing the 8.8.

I had a buddy just call me with a ranger rear last week but he hasn't got back to me on exactly what it is. I think it's not an 8.8 but the smaller one they used, early to mid 90s. Even then the ranger 8.8 is not nearly as strong as the explorer 8.8. different spline count, different axle shaft thickness.

From what I see all the 8.8s weather in a ranger, mustang, or explorer use the same length short side axle and then use a different length long side to get the overall length. The mustang guys always pilfer the short side ranger axles to convert to 5 lug pattern.

I often wonder if those talking about weak 8.8s are talking about explorer 8.8s or if they have a mustang or ranger 8.8.

Sorry, forgot it was for an F-body. Just glanced at it real quick. I didn't know the ranger rears were lighter duty.

 

[dusterbd13]

im shocked to see this thread come back.

i did bite the bullet and put 900 into my 8.75.

i have killed it again already. less than 3k on it.

the rearend guy is going to stand behind it and warrenty it, though. this was with a 400 at the wheels small block on 240 treadwear tires. and a 4 speed. granted i autocross the car, and its not light with all the extras ive added, but i shouldnt be killing them like i am.

if i ind a good 3.73 locker rear disc 8.8 in the yards, im going for it. according to my measurements and others, with a nice smack to my one muffler it should fit fine. well see.

and also, all the 8.8 bashing vs cheap 8.75 talk: find me a cheap one, and ill still break it. go look under my buddies american iron extreme fox body with the 331 and hoosier a6's. its rocking a factory issue 8.8 with over 300k on it before it was turned to a race car. apples to oranges, but says something. i know that both rears have their good and bad points, and this was never meant to be a discussion of either. it was meant to be a discussion of putting a stock width 8.8 into an a-body with no mods other than spring perches. other than jamesdart, i have yet to see anyone else do it. and ive never seen pictures of his. just measurements.

michael

 

[pupjoint]

Idid not make any mods to my explorer rearend other than new spring perches. Did not shorten any side, but did weld the tube to the diff.

 

[RedFish]

Idid not make any mods to my explorer rearend other than new spring perches. Did not shorten any side, but did weld the tube to the diff.

Its been said that one axle and tube is longer than the other in those Ford rears. If that is true and you welded perches equal distance from the center, wouldn't one tire sit farther out from under the car ?
I read somewhere that a guy bought parts needed to install the shorther axle and tube in both sides of that rear and it fit the A-body perfectly.
I couldn't post to this thread when the guy asked for experience with this swap because I have none.
Opinions on using a Ford rear isn't what he asked for and I didnt have one of those anyway.

 

[pupjoint]

I don,t have any issues with tire centers,I may not have done it the correct way but I do not have any issues.

 

[Idaho]

I dont think they used risidual valves for years, that is old tech, modern drums and any repair parts include a new style piston cup that doesnt need a few lbs to force the lip against the cylinder. Case in point. When was the last time you cracked the rear brake bleeder and had 10psi fluid shoot out, never? I cannot recall a time. I believe the 8.8 has small drum E brakes in the rotor hubs. I dont have the one I did as the guy had the brakes off when I cut it. 2 short axles, 3 inches off the long side tube and reweld, lay it up in there and mark for new perches. Get yourself a bolt on yoke for a 1350 U and then get a 1350 end on your driveshaft. Mustangs already have equal side shafts. adjustable prop valve and your set. Do it, or build another 8.75 SBP rear with 40 year old parts. The 8.8 will cost less than a set of 8.75 gears and bearings.....

Good to know. Thanks.

 

[dusterbd13]

I don,t have any issues with tire centers,I may not have done it the correct way but I do not have any issues.

Do you have any pics? Especially of the driveshafyt in the tunnel?

 

[Supershafts]

Based on the article above, those of us putting an 8.8 with discs where there were drums should be making sure we have no residual valve. I've read everything I've seen on the 8.8 swap here and not seen this discussed.

I agree, because if I remember, the residual pressure check valve is needed to keep aout 8-10psi on drums to prevent dirt and debries from entering the brake system through the wheel cylinder.

I was once considering an 8.8 swap and retaining my front drums till I can afford a BBP disc swap.

To do that, I would need a an inline proporting valve (adjustable) to control brake bias, as well as an inline metering valve to keep the discs from activating untill sufficent pressure (60-80psi) is on the drums to overcome to springs to prevent the rear wheels from locking up under hard braking. Lastly the MC would have to be changed because on vehicles with 4-wheel drums, the residual pressure check valve is built in to the master cylinder and the residual pressure on the rear circuit would cause the brakes to drag back there.

Moreover a vehicle considering this swap with front disc brakes, adding the 8.8 with discs to the rear would eliminate the need for a residual pressure check valve as well as a metering valve. The only thing required would be the adjustable proportioning valves on both circuits.

Residual valves don't have a damn thing to do with keeping dirt or any other nonsense out of the brakes or wheel cylinders, and residual valves aren't used with drum brakes, please do not advise anyone on brakes, YOU are going to get them KILLED...

Prop valve is different than a residual valve, there are many different residual valves...

Drum brakes are ADJUSTED and held within a measured amount from the drum by a slack adjuster at the bottom between both shoes, the springs hold the shoes together and push the pistons into the wheel cylinder and that gives you that amount of throw on the master piston to move enough fluid to activate and work the brakes... This adjustment also helps warn you when they need adjustment as the pedal will no longer be high and firm..


Now you add discs into a drum disc system and what happens is everytime you release the brake the piston in the caliper retreats, it does so by the rotor bumping the pads and instead of the caliper floating with the pads over the rotor the piston retreats to far and you have a problem, now without a residual valve holding some psi on the line it retreats to far and the pads become to far from the rotor and then when you hit the pedal you do not get the right amount of psi on the piston BECAUSE you do not have enough fluid flow for the amount of piston travel in the master and that in turn has less force on the pad and that in turn has YOUR front pads now doing 90% of the work all the time, and you THINK you have rear brakes...

I didn't go thru all of that because you know, i went thru all of that because i know you don't know and thats why i bothered to interject to the unknown of how brakes work since i seen NO ONE knew..

Now you do, and you NEED a residual valve.

I answered the op also, whether or not you like the answer is another issue.
.

 

[RedFish]

The only retract action in a disc brake caliper is caused by a square ring instead of an O ring. If a rotor has enough runout to push a piston back into the caliper that rotor needs to be replaced.
There is a small amount of residual pressure in every antilock brake system. It isn't enough to heat parts, accerate lining wear, or cause any other ill effects.

 

[pupjoint]

I,m sorry I am in south Mexico right now want be home for another 25 days, but I can get you some when I get back to the states. The 8.8 has been in the car for over 3 years, I do not have any vibration problems and havent had any other problems.