TH400 cracked
#1
TH400 bellhousing cracked
Look what i found under the car today when i was changing left exhaust manifold!?
Looks like i have some welding to do...
It's a good thing that i noticed this at this point.. because if those last bolts had been broken all hell would have been loose.
What has caused this crack? Too much torq?
I bet those bolts have been too lose.
Looks like i have some welding to do...
It's a good thing that i noticed this at this point.. because if those last bolts had been broken all hell would have been loose.
What has caused this crack? Too much torq?
I bet those bolts have been too lose.
Last edited by Delta88conv455; August 1st, 2013 at 07:56 AM.
#5
I can't recall the details, but someone I used to talk with online had that happen to an automatic, and he got a replacement for just the bellhousing. Cut off the cracked cast from the trans body and the new one bolted up (I think) using the pump bolts to hold it on. I know it's common with manuals, but this was definitely for an automatic. Might be worth the time to look into it.
Found it.
http://www.summitracing.com/search/b...ion-type/th400
Found it.
http://www.summitracing.com/search/b...ion-type/th400
Last edited by Professur; July 31st, 2013 at 09:57 AM.
#6
Nice work. Something came unglued. Maybe a flex plate bolt or converter bolt? Or someone installed it wrong by not fully engaging the dowel pins and tightened her down anyway. Gota love the shade trees...Is the converter damaged too?
IMO DO NOT drive it! If in fact their is more damage than just the case which would be hard to believe there isnt, a flex plate will sheer through a floor tunnel and sheer your foot (feet) off.
Get a new case or a new trans. Welding old dirty aluminum is tricky it can cause brittle spots. Id be leery of driving it after welding. You want confidence dont you? As well as safety. TCI sells great street n strip trannys for around $1100. Put the numbers matching case on the shelf and call it a day.
IMO DO NOT drive it! If in fact their is more damage than just the case which would be hard to believe there isnt, a flex plate will sheer through a floor tunnel and sheer your foot (feet) off.
Get a new case or a new trans. Welding old dirty aluminum is tricky it can cause brittle spots. Id be leery of driving it after welding. You want confidence dont you? As well as safety. TCI sells great street n strip trannys for around $1100. Put the numbers matching case on the shelf and call it a day.
#7
This is probably more than you want to spend, but it would probably be your best and safest bet for repairing that case.
http://www.summitracing.com/search/p...l-bellhousings
http://www.summitracing.com/search/p...l-bellhousings
#9
Am I mistaken, or is that ALL of the attachment points on one side?
I agree that this looks like an installation error, rather than too much torque.
If you are a VERY good aluminum welder you could weld this, otherwise, it's new trans time.
Used long-tail TH400s are not hard to find or expensive.
- Eric
edit:
ps -
1. Change the flex plate as well - once the flex plate has done some flexing, it's had it.
2. post those pics on the "Wall of Shame" thread, 'cause someone really screwed up there!
I agree that this looks like an installation error, rather than too much torque.
If you are a VERY good aluminum welder you could weld this, otherwise, it's new trans time.
Used long-tail TH400s are not hard to find or expensive.
- Eric
edit:
ps -
1. Change the flex plate as well - once the flex plate has done some flexing, it's had it.
2. post those pics on the "Wall of Shame" thread, 'cause someone really screwed up there!
Last edited by MDchanic; August 1st, 2013 at 03:58 AM.
#10
Well... i'll get a transmission jack today and then i will get a better look at this disaster.
Looks like 4 out of 6 attachment points are loose...
I have a professional welder friend so he shall have to look at it.
Sure there has been a TRUE MECHANIC at work here..
Cracks looks like old ones, so there has been some GOOD LUCK.
I'll post some sad pictures as soon as i get the tranny out.
And thank you all very much for advice! My english ain't so good so sorry for any misspelling.
Looks like 4 out of 6 attachment points are loose...
I have a professional welder friend so he shall have to look at it.
Sure there has been a TRUE MECHANIC at work here..
Cracks looks like old ones, so there has been some GOOD LUCK.
I'll post some sad pictures as soon as i get the tranny out.
And thank you all very much for advice! My english ain't so good so sorry for any misspelling.
Last edited by Delta88conv455; August 1st, 2013 at 05:06 AM.
#15
Pins are fine and left hole is fine but right one is missing a little piece.
Flex plate and turbine is fine and tranny worked very well as i was driving.
I did not notice anything wrong while driving.
Flex plate and turbine is fine and tranny worked very well as i was driving.
I did not notice anything wrong while driving.
#16
There's not a lot I wouldn't give to a good welder .... but I wouldn't give that. Yes, a good welder could save it, but nothing takes a beating like that well. You're going to have metal fatigue through out the piece. A welder that knows metallurgy would be the only one I'd ask to attempt it.
#17
I'd have no problem welding one tab on the bellhousing, but this is probably not worth it. My biggest concern is loosing registration of the passenger side dowel pin. If you loose concentricity of the trans with the crank, you'll have problems in the long run. I'd either get a different case or a Super Bell.
#18
Not to be contradictory, but TH-400s are nearly indestructible in ordinary use, full size cars are in low demand and are being stripped and scrapped constantly, and the long-tail transmissions from these are in relatively low demand.
I'd recommend buying a used trans. from a junked car over your alternatives, for a non-souped-up daily driver like this.
- Eric
I'd recommend buying a used trans. from a junked car over your alternatives, for a non-souped-up daily driver like this.
- Eric
#19
Not to be contradictory, but TH-400s are nearly indestructible in ordinary use, full size cars are in low demand and are being stripped and scrapped constantly, and the long-tail transmissions from these are in relatively low demand.
I'd recommend buying a used trans. from a junked car over your alternatives, for a non-souped-up daily driver like this.
- Eric
I'd recommend buying a used trans. from a junked car over your alternatives, for a non-souped-up daily driver like this.
- Eric
#20
I figured B bodies would be in fairly generous supply, having been the core of every police force forever ... only to discover that one local boneyard had brought in a shredder and virtually wiped out the 400 former cop cars they had. Old heavy cars for them are $$$ in metal. Less so in parts.
#22
Allright, the wisest thing would be a new tranny, i get that.
My professional welder friend looked at gearbox and he said that it can be done.
We are going to take a block and attach box to it so that tranny will line-up with engine.
He will weld bellhousing and reinforce it.
So lets just see how he does his miracles, and what is the result.
But i am going to be looking for a used non-welded case in the future.
My professional welder friend looked at gearbox and he said that it can be done.
We are going to take a block and attach box to it so that tranny will line-up with engine.
He will weld bellhousing and reinforce it.
So lets just see how he does his miracles, and what is the result.
But i am going to be looking for a used non-welded case in the future.
#23
#26
I think I agree.
However with a little JB weld and some duct tape, it will be as good as new in no time!
#27
Nope. The missing piece is gone
But the hole is only about inch by inch wide so it can be done by welding.
And one thing is good that location holes are in place, though right one is little bit broken. I checked flexplate by measuring and its ok which is kinda weird because there was only one bolt holding... talk about luck
But the hole is only about inch by inch wide so it can be done by welding.
And one thing is good that location holes are in place, though right one is little bit broken. I checked flexplate by measuring and its ok which is kinda weird because there was only one bolt holding... talk about luck
#31
Thanks very much for the offer Seff, but it just turned out that a friend of mine has a TH400 at 20miles far from my house
The only thing is that it has a short tail. My tranny has a 9" tail. Well a few inch more to propeller shaft would do the trick
The only thing is that it has a short tail. My tranny has a 9" tail. Well a few inch more to propeller shaft would do the trick
#32
That sounds much easier.
This guy had some of the same problems: http://www.chevelles.com/forums/showthread.php?t=255244
Seems like you could change the needed parts over from your broken transmission and put them in your new one.
This guy had some of the same problems: http://www.chevelles.com/forums/showthread.php?t=255244
Seems like you could change the needed parts over from your broken transmission and put them in your new one.
#33
TH400hitsattuna (3) small.jpgAll welded up!
Was a easy thing to weld. Lets just see how this works..
Was a easy thing to weld. Lets just see how this works..
Last edited by Delta88conv455; August 7th, 2013 at 11:49 AM.