C3 manual transmission case damage
#21
Intermediate
Thread Starter
Transmission looks nice and clean inside. If you don’t mind the effort, might be a good tie to change the fluid and check the differential, just to be sure that wasn’t the cause.
I would suggest getting yourself a drive shaft loop if you don’t find a definitive cause. Cheap insurance if it happens again. You got lucky this time but catapulting doesn’t sound like a lot of fun, though I don’t think it’s easy for the drive shaft to drop that far.
I would suggest getting yourself a drive shaft loop if you don’t find a definitive cause. Cheap insurance if it happens again. You got lucky this time but catapulting doesn’t sound like a lot of fun, though I don’t think it’s easy for the drive shaft to drop that far.
What is a drive shaft loop? Never heard of such a thing.
#22
Melting Slicks
Frt bearing support just 4 bolts to frt of trans.
I would suggest you get a manual on rebuilding /parts diagrams printed out.if bellhousing is cracked its time for a new on. Can you shoot some pics of the cracks on bellhousing and post.
Since you're going to have it out probably need synchros replaced nd forks checked at a minimum.
I would suggest you get a manual on rebuilding /parts diagrams printed out.if bellhousing is cracked its time for a new on. Can you shoot some pics of the cracks on bellhousing and post.
Since you're going to have it out probably need synchros replaced nd forks checked at a minimum.
#23
Intermediate
Thread Starter
Rodnok1, pictures of the cracks in the bell housing are below.
I definitely want to take this opportunity to partially rebuild the transmission. I need a new case (main, tail and bearing support). What other parts do you recommend I replace/update? Additionally, I will replace the bell housing, cross member, drive shaft and u-joint.
I definitely want to take this opportunity to partially rebuild the transmission. I need a new case (main, tail and bearing support). What other parts do you recommend I replace/update? Additionally, I will replace the bell housing, cross member, drive shaft and u-joint.
#24
Drifting
Almost looks like it got into two gears at the same time. Kind of like you would do to lock the trans up to loosen or tighten something. I've seen the incorrect slider lock up, but right after a rebuild. I wonder if the shifter could be the source of the first harmful event?
#25
Melting Slicks
Impressive carnage, and glad you did not get hurt.
Rodnok1, pictures of the cracks in the bell housing are below.
I definitely want to take this opportunity to partially rebuild the transmission. I need a new case (main, tail and bearing support). What other parts do you recommend I replace/update? Additionally, I will replace the bell housing, cross member, drive shaft and u-joint.
I definitely want to take this opportunity to partially rebuild the transmission. I need a new case (main, tail and bearing support). What other parts do you recommend I replace/update? Additionally, I will replace the bell housing, cross member, drive shaft and u-joint.
Impressive carnage and glad you did not get hurt.
I am told that you can reweld the broken 4speed "ears" that mount the transmission to the bell housing. However, if you decide to replace the main case, please send me a PM as I have a 4sp case missing an ear so I would be happy to buy your broken "ear" pieces to save me from having to fab one from scratch.
Good luck on the repair and thanks for sharing any learnings that surface.
Here is are some great resource books for 4 speeds:
This guy Paul Cangialosi writes some super books on how to rebuild your 4sp that are most informative.
Last edited by 20mercury; 06-04-2018 at 12:05 AM.
#26
Intermediate
Thread Starter
20mercury, I hadn't thought about the possibility of welding the ears back on. I will look into it. This is going to be an expensive repair, so I'd like to save the main case, if possible.
I'll keep updating this thread as I make progress on the repair. Any insights or thoughts as I go would be welcome and much associated. Thanks.
I'll keep updating this thread as I make progress on the repair. Any insights or thoughts as I go would be welcome and much associated. Thanks.
#27
Melting Slicks
Totally missed the 2 ears snapped off the main case...
Not cheap to have welded back on, easier to get a different case.
Thats alot of damage period, short of a trans grenading I haven't seen one that bad. Frankly it's about a total loss unfortunately.
The rear mount more than likely is broken to allow the trans to moventhat much. Regardless you've got alot of work and $ ahead...
Not cheap to have welded back on, easier to get a different case.
Thats alot of damage period, short of a trans grenading I haven't seen one that bad. Frankly it's about a total loss unfortunately.
The rear mount more than likely is broken to allow the trans to moventhat much. Regardless you've got alot of work and $ ahead...
#28
Intermediate
Thread Starter
Totally missed the 2 ears snapped off the main case...
Not cheap to have welded back on, easier to get a different case.
Thats alot of damage period, short of a trans grenading I haven't seen one that bad. Frankly it's about a total loss unfortunately.
The rear mount more than likely is broken to allow the trans to moventhat much. Regardless you've got alot of work and $ ahead...
Not cheap to have welded back on, easier to get a different case.
Thats alot of damage period, short of a trans grenading I haven't seen one that bad. Frankly it's about a total loss unfortunately.
The rear mount more than likely is broken to allow the trans to moventhat much. Regardless you've got alot of work and $ ahead...
So far, here's what I'm lookin' at:
Bell housing $200
T10 Main case $250
T10 tail housing $200 (thegearbox.org)
T10 rebuild: synchro and forks ???
Drive shaft $300
Slip yoke: $200
Cross member $400
U-joint $30
Parking brake cable $50
#29
Racer
A friend had this happen on the chassis dyno(clip came out of front u-joint)...
Put the clutch in as soon as he could but still...
Broke the bell housing, main case, tail housing just light yours, but also broke the main shaft and bent the input gear and broke 2 teeth off the input and 4 off the cluster gear...
What I'm getting at is you need check all the internals of the trans to make sure everything is straight and true...
Hope this helps... Eric
Put the clutch in as soon as he could but still...
Broke the bell housing, main case, tail housing just light yours, but also broke the main shaft and bent the input gear and broke 2 teeth off the input and 4 off the cluster gear...
What I'm getting at is you need check all the internals of the trans to make sure everything is straight and true...
Hope this helps... Eric
#30
Intermediate
Thread Starter
A friend had this happen on the chassis dyno(clip came out of front u-joint)...
Put the clutch in as soon as he could but still...
Broke the bell housing, main case, tail housing just light yours, but also broke the main shaft and bent the input gear and broke 2 teeth off the input and 4 off the cluster gear...
What I'm getting at is you need check all the internals of the trans to make sure everything is straight and true...
Hope this helps... Eric
Put the clutch in as soon as he could but still...
Broke the bell housing, main case, tail housing just light yours, but also broke the main shaft and bent the input gear and broke 2 teeth off the input and 4 off the cluster gear...
What I'm getting at is you need check all the internals of the trans to make sure everything is straight and true...
Hope this helps... Eric
Thanks, Eric. This is very, very helpful. This gives me confidence that I'm headed down the right track. I will DEFINITELY get the transmission thoroughly inspected. Visual and rudimentary mechanical inspection reveals: NO shavings or metal deposits in the fluid or bottom of case, main shaft appears to turn easy and true.
#31
Intermediate
Thread Starter
Well, just when I thought I had spotted all of the damage, and was narrowing in on a total cost of repair, I discovered that the output/main shaft on the T10 transmission is not turning true...it is easy to see it shifting off center as it turns. That increases my cost considerably as I believe I need a new transmission. Anybody have any ideas?
#32
Consider it an opportunity to get an Overdrive transmission. Once of the best mods I made to mine.
What kind of money do you have available? That's the big question.
Look around and see if you can find a Richmond 5 or 6 Speed. They kinda/sorta bolt in and can use the existing driveshaft (mine did with the appropriate u-joint). Not sure of prices though.....
I would have been nervous about re-using that tranny anyway. Did you ever determine the root cause?
What kind of money do you have available? That's the big question.
Look around and see if you can find a Richmond 5 or 6 Speed. They kinda/sorta bolt in and can use the existing driveshaft (mine did with the appropriate u-joint). Not sure of prices though.....
I would have been nervous about re-using that tranny anyway. Did you ever determine the root cause?
Well, just when I thought I had spotted all of the damage, and was narrowing in on a total cost of repair, I discovered that the output/main shaft on the T10 transmission is not turning true...it is easy to see it shifting off center as it turns. That increases my cost considerably as I believe I need a new transmission. Anybody have any ideas?
Last edited by carriljc; 06-07-2018 at 10:59 PM.
#33
Melting Slicks
My 2 cents,....
My 2 cents, while I and many others would like to salvage the original 4sp since the numbers match. IMHO, a more practical and cheaper answer that I would pursue is go find another 4sp on ebay or here on the forum. These 4sp's are pretty tough and I think you can find a used one that would still give you lots of years of service without having to rebuild it. Particularly if you can find out the history and talk with a seller that knows where it came from.
Hope this helps and good luck with the fix whatever you decide.
Hope this helps and good luck with the fix whatever you decide.
#34
Intermediate
Thread Starter
Root cause: front u-joint failure.
I'm still debating what to do about the transmission. The 4speed works fine for me the way I use/drive the car. I don't really see a need to "upgrade." However, I don't ever intend to display/show the car either, so no major pull to stay original. So, the decision is coming down to what I want to learn, what I have time and money for. I'm leaning towards rebuilding the transmission, mainly because I think I can do it, and will enjoy it, and because the innards of the transmission look really good (car only has 47k miles).
I can get a new main shaft, tig weld the ears of the main case, new tail housing, rebuild kit, all for about $500 - $700.
I might start a new thread for some help on this.
I'm still debating what to do about the transmission. The 4speed works fine for me the way I use/drive the car. I don't really see a need to "upgrade." However, I don't ever intend to display/show the car either, so no major pull to stay original. So, the decision is coming down to what I want to learn, what I have time and money for. I'm leaning towards rebuilding the transmission, mainly because I think I can do it, and will enjoy it, and because the innards of the transmission look really good (car only has 47k miles).
I can get a new main shaft, tig weld the ears of the main case, new tail housing, rebuild kit, all for about $500 - $700.
I might start a new thread for some help on this.
#35
Intermediate
Thread Starter
I'm not sure anyone's following this anymore, but I like to finish what I start. So, here's what's going on now: I found a welder with a good reputation, so I'm gonna have him tig weld the ears back on. In the mean time, I opened up the transmission and discovered the internals look like new...makes sense given that it only has 47k miles on it. Previous owner was literally an old lady...it appears she drove like one (haha!). Anyway, the bend in the main shaft is at the main seal, not inside the case. So, I believe the internals are unharmed by the violent incident. So, I've decided to get a new main shaft (~$160), weld the ears ($150), and a rebuild kit (~$125), and put it all back together. I know I'm rolling the dice that the internals don't have any cracks or weak spots, but I'm impressed with how good it looks inside, I'm willing to take the risk. pictures to follow:
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20mercury (06-19-2018)
#36
Intermediate
Thread Starter
I believe the source of the violent incident, and all of this damage, is a snapped bolt on one of the straps on the u-joint. See the picture below.
It appears to me that the bottom right bolt broke...all of the others were sheared off.
Bottom left is the bolt that broke. Maybe it was on too tight?
It appears to me that the bottom right bolt broke...all of the others were sheared off.
Bottom left is the bolt that broke. Maybe it was on too tight?
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20mercury (06-19-2018)
#40
Intermediate
Thread Starter
Got the main case back from the welder today. It appears that he did a really good job. Cost $150 (I know this is expensive), but he came HIGHLY recommended by a GM certified mechanic. I decided it was worth the extra $50 or so for the confidence it is done well. Below are the pictures. Now that I have the main case, I plan to begin buying replacement parts, beginning with a new main shaft. Found one for $155 plus shipping. Pretty happy with that price. I will also buy a tail shaft ($200) and a ST10 rebuild kit ($150).