Torque converter bolts got loose, now it won't move at all

[Joe T]

Was driving home my 71 c10 from getting freshly painted and noticed it would slip when hitting the gas. I thought i was low on fluid so I continued to drive and then it started to make a rattling sound...I was only a few miles from home so i figured just get home and fix it.

I opened up the pan and 2 out of 3 of the bolts were off! I knew i should have used some thread sealer. Damn!

So I bolted it back on hoping that would fix it but now it won't go anywhere. So I guess I messed up something driving it home. Damn!

It's a shorty th350 that hasn't given me any trouble at all. Do you think the whole transmission is shot or just the converter?

[Richard]

I would guess that the loose converter wobbling around destroyed the pump in the transmission.

[Accelo]

I have seen many a convertor come loose and never had one destroy the pump. However, it could conceivably happen. How many miles on the transmission? You can check for a pump failure by disconnecting a cooler line and see if its pumping oil. If not the pump is indeed bad. It can be the converter was not correctly spaced from the flex plate. Either too tight or too loose will cause the pump to fail. Too tight is typically an immediate failure. So the odds are it was not fully engaged at the pump and the converter looseness was all it took to do the final wearing on the pump lugs. If you have no transmission oil pressure/cooler flow it will have to come out. Then you can inspect the converter snout and the pump lugs to see where you need to go next.
This is the longer version of what Richard indicated.

[Joe T]

Thanks, ill check out if the pump is bad. Found an old buick th350 for 150 bucks, looks like it will fit with an adapter plate, anybody ever bolt up one like that to a chevy?

[Jiggers72-GMC]

Joe, just use the pump and the torque out of the Buick trans, it's easy to swap ........

[Accelo]

[QUOTE=J Found an old buick th350 for 150 bucks, looks like it will fit with an adapter plate, anybody ever bolt up one like that to a chevy?[/QUOTE]

Some Buick transmissions are BOP pattern. Buick, Olds, Pontiac.
Some are the corporate case which will fit both the SBC's and the BOP.
So the answer is depends on what year. It certainly would be less expensive to find one that fits without the adapter. Or switch pumps. Still have to confirm you are not mixing lock up 350 pumps with non-lock up pumps.

[Jiggers72-GMC]

Exactly, ^^^^^^ what Accelo said.

[old51sedan]

Originally Posted by Joe T

Thanks, ill check out if the pump is bad. Found an old buick th350 for 150 bucks, looks like it will fit with an adapter plate, anybody ever bolt up one like that to a chevy?

I believe if it was mine I would try to find a 200-R4 in the bone yard. For about the same money you could have an automatic overdrive. It should slide right in, just slide the trans crossmember back and the drive shaft should fit with no problem. That's what I did with mine, easy peeze. They came in most all makes go GM cars in the eighty's and because of their bolt pattern will bolt up to almost any GM product. I would measure your 350 as I believe they made a couple of different lengths. The best ones to look for came in the 442's, GTO's, monty Carlo SS, they have a better valve body in them, but almost any of them will work.

[Jiggers72-GMC]

That's a good idea as well ^^^^ good time to upgrade to overdrive ..........

[Joe T]

Cool, im picking it up today, hoping its the same length, if not ill do the pump and converter swap, thanks for all the help, ill post some pics soon!

[body bolt]

Here's a list of cars that used the TH200-4R.

https://transmissioncenter.net/blog/...ion-spotlight/

[Joe T]

picked up the transmission, it's out of a 70 skylark, so it's exactly the same length as the chevy. guy said it works great so i ordered the converter plate and will swap it next week.



not bad for maaco!

[Joe T]

so i tried to bolt up the buick tranny with the adapter plate but the original torque converter was too big! I need a low profile one, stock stall speed, anybody got any recommendations? not looking for anything fancy, i drive this about 100 miles a year. saw this one at autozone, wonder if it will fit the th350 (I think power glides are different? this is what came up when i put in my truck) :

https://www.autozone.com/drivetrain/...-b3/263397_0_0

[Jiggers72-GMC]

Yes that torque will fit a TH350 (and a TH400), as long as your trans is NOT lockup and yes Power Glides are different

[Steeveedee]

Are you certain that you got the converter all the way into the front pump?

[Joe T]

Originally Posted by Steeveedee

Are you certain that you got the converter all the way into the front pump?

definitely. we measured the pads on them and the old buick one was a quarter inch longer. so we put the old junk chevy converter in the buick and it fit just fine.

as for the lockup, non-lock up, i read it's for towing. but what about loading heavy **** in the bed, does that matter? will probably just go with non-lockup.

[MARKDTN]

TH350 and TH400 converters interchange. I am not aware of different "low-profile" versions. I would also think that it did not go the second click into the pump as suggested above. If you rotate the converter while pushing gently as you install it it should have 2 different times that it clicks in. You can roughly measure rear block face to back of flexplate and the converter lugs should be a little more than that same difference back from the front face of the transmission. If you don't get 2 clicks or the converter is not far enough in, it will not work.

[Jiggers72-GMC]

Good luck Joe

[Jiggers72-GMC]

Originally Posted by Joe T

as for the lockup, non-lock up, i read it's for towing. but what about loading heavy **** in the bed, does that matter? will probably just go with non-lockup.

If that Buick trans you got is a 'lockup' style, a regular th350 torque won't fit on the input shaft, that's the point I was trying to make,
this is a lock up and no lockup
https://www.thirdgen.org/forums/atta...50vsth350c.jpg

[Joe T]

Originally Posted by Jiggers72-GMC

If that Buick trans you got is a 'lockup' style, a regular th350 torque won't fit on the input shaft, that's the point I was trying to make,
this is a lock up and no lockup
https://www.thirdgen.org/forums/atta...50vsth350c.jpg

I checked and it's the non-lockup version, so new torque converter worked great, back on the road! The B&M converter plate worked like a charm. Thanks for everyone's help, got this job done for under 300 bucks!

[Jiggers72-GMC]

Glad to hear it man, right on, good for you!!!!