Damaged trans?

-
kempkan

kempkan

Well-Known Member
Joined
Jun 30, 2009
Messages
166
Reaction score
2
Location
Latrobe, Pa
I went to the track yesterday and on my second time trial I snapped my u joint off the launch. My car is only a 13.90 in the 1/4 with a 318 and 4.56 gears. My question is with that u joint snapping in first gear could I have damaged the 904 I have in it. The car isn't a monster by any means and didn't know if that mattered or not.
 
Time to crawl under that begger and take a look. If the front yoke is still intact and hanging on the output shaft, probably not. If you exploded the front yoke like I did once, you might find the transmission extension housing in pieces, most of them gone. I found several laying on the ground and not even close to the path of the car. Brake cables kept the shaft from turning into a pogo stick. If the output shaft splines are twisted, you've probably found a contributor to the early demise of the u-joint.
 
I didn't see anything externally I was worried about the internal part of the tranny. It was actually the rear u joint that left go. Luckily I have a driveshaft loop that held the shaft from flopping around too much. The drive shaft took a pretty good hit though. The end that hit the ground is dinged up pretty good and im sending it out Monday to have it checked and possibly rebalanced. Once I get it on the rack tomorrow I will check the extension housing real good. So more than likely the internals are good?
 
What type of valve body in the trans ? If it's a manual VB does it have low band apply ?
 
I did the same thing. Totally wiped out the front U joint. I didn't think much
of it at the time. But I did put a big long crack in the tail housing. Had another
driveshaft that I put in and drove it. I had a vibration. It made the crack
even worse. Started leakin all over the place. Took it out to find the housing
bad and then took the trans apart. was told to check the rear over run
springs and bearings. You can colapse the springs and cause more damage.
Mine were ok. Don't chance it.
I did have to spend over a $100.00 to get the tail housing welded. It is the
one with the bracket on it for the floor shifter.
Take your time and do it right the first time. Good luck. Keep us posted
on what you find.
 
Did you leave low rpm or do you have a fairly good TC, if it broke at launch at a low rpm then your trans internals are probably ok, and probably even the tailhousing.
 
I have a 3500 stall but starts pushing me through the lights at about 1800-1900 rpm. When it snapped I hit the rev limiter at 6200 then immediately shut it down. Oh I just found my problem by the way. The yahoo who welded my perch plates on for my relocation didn't do a great job at all. My diff is spinning on the perch plates. I bet it twisted changing the pinion angle then boom. Well he's done doing my welding. I don't see any cracks in the tailshaft but im going to drop the cross member to make sure. These are times I wish I had a welder.
 
67Dart273 said:
I'm no expert on TF's but from what I've read I would pull it apart and check the rear sprag for damage.

http://www.bigblockdart.com/forum/s...ion.-(Posted-first-pics-in-a-different-thread
Click to expand...

I am, and you better pull the trans and inspect or replace the over running clutch in the rear of the trans. If it's damaged as will likely happen when breaking a driveline under power in 1st gear the next pass could end up with the trans exploding and injuring you, a bystander (I've seen pieces fly into the stands and injure spectators), and your car. Cheaper in the long run, paper and seal kits are cheap as are the race, roller and spring kits.
 
67Dart273 said:
I'm no expert on TF's but from what I've read I would pull it apart and check the rear sprag for damage.

http://www.bigblockdart.com/forum/s...ion.-(Posted-first-pics-in-a-different-thread
Click to expand...


Guitar Jones said:
I am, and you better pull the trans and inspect or replace the over running clutch .
Click to expand...

Thank you. Thank you very much

Elvis.gif
 
Not what I wanted to read but it my save the tranny in the end. Where can I get the sprag kit? Does places like summit or mancini offer them? Anything I can do to add strength while im in the while being on a budget? I was getting a vibration off the launch now that I thought about it after I read those postings too. Im hoping I can rebuild it myself I am not to fimiliar with trannys I've done one in my life and I believe it was a 4L60E out of a chev truck. Might as well do a complete rebuild with clutches and bands too. Thatnks for the reading materials guys.
 
I was reading in that posting to about jacking up the car and putting it in neutral and if it spins freely both ways its bad and if one way its harder than the other. Any truth to this?
 
Guitar Jones said:
I am, and you better pull the trans and inspect or replace the over running clutch in the rear of the trans. If it's damaged as will likely happen when breaking a driveline under power in 1st gear the next pass could end up with the trans exploding and injuring you, a bystander (I've seen pieces fly into the stands and injure spectators), and your car. Cheaper in the long run, paper and seal kits are cheap as are the race, roller and spring kits.
Click to expand...
I couldn't agree more. As soon as I read the first post I was thinking sprag.
 
I decided im pulling it. Its better safe than sorry. Not worth it hurting myself or someone else. I think a rebuild is in order as well. Like I said I have a 904. Any suggestions on what I need or what is should use? Rebuild kit, bolt in sprag for a 904, etc?I need some guidance.
 
Good choice.Feet aint cheap.Search up the thread exploding torqueflites,good read. If I,m not mistaken Chris Andrews wrote it.
 
I did read the posting chris wrote. Everything mentioned is a 727. I guess the rotating mass of a 904 is alot less. So do it really need a new drum? A bolt in sprag? Everyone is doing these thing to a 727 but what about my little 904? While im in there I may as well do it I just need to know what to do. I want to thank you guys and fabo for all the knowledgeable people I love this site.
 
I have to tell you, I would NOT take the chance. Back in 68, the guy who would become the original owner of my 70 sixpack RR had a 65 Chevelle with a 350/ 4 speed from a wrecked Camaroo, and we'd put a 350HP cam in the thing. It ran pretty damn good.

We were going to Navy schools at Treasure Island, and he pulled a "big" 1-2 shift on the on ramp from T.I. to San Fran. Ker -- freeckin' -- blaooey!!

We got 'er back to the base, bought a junkyard (10 bolt) axle, and put it together. IT WOULD NOT MOVE!!!

The shock of the rear axle breakage had SNAPPED THE input shaft of the Muncie IN HALF!!!

See the groove in the middle of the splines? I have no idea why it's there, but that is where it broke

muncie_input_shaft_50_holgate_8380854.jpg
 
i broke my driveshaft at MATS...i removed and replaced the rear sprag...did not think twice about...the 904 drum will not explode like a 727 due to its smaller size..

you can buy the spring and roller kit from bulkpart.com for a few bucks....i replaced the complete assembly with a new one..cause i had one...

several years ago i broke a ring gear on a car with 904....and raced it at the next race...after a couple of passes the trans was making all kinds of noise..the spraq was damaged..
 
Pull it and check the sprag and tailshaft.

Like Tony mentions about explosion risk, I've NEVER seen a 904 explode like a 727 does. They just don't turn enough RPM to grenade the drum. That would all change if you had a 10K+ rpm screamer... then it might happen.
 
crackedback said:
Pull it and check the sprag and tailshaft.

Like Tony mentions about explosion risk, I've NEVER seen a 904 explode like a 727 does. They just don't turn enough RPM to grenade the drum. That would all change if you had a 10K+ rpm screamer... then it might happen.
Click to expand...


well..my 904 hit 8000 rpm...went the driveshaft broke as the engine with the high side chip...8k...and transbrake is a non low band apply valve body....

but now i have a CRS super shield just in case...
 
Yes I have never seen a 904 explode a drum either, probably just because of the smaller mass. However it's still possible for it to do it, I wouldn't be over confident that it wouldn't explode and never say never.

The 727 outer race is pressed into the case and they tend to break the case when they roll. Thus the need for a bolt in sprag. The 904 already has a bolt in or riveted in rear sprag already so buying one isn't necessary unless yours is damaged.

A basic stock rebuild is fine for your application, mine is pretty much stock with a 5 disc front clutch, and an A500 front pump with the flat drive pump hub on the converter. That's the only thing I've really broken in my 904 is the converter drive hub.
 
You must log in or register to reply here.
-

Back
Top