Question: TH350 tranny issue

[A1Avette79]

I posted a thread back in 2012. I'm still having the same issue with my tranny - it seems to be getting worse. I have a 79 (early), L48, auto transmission TH350. I had to replace the fly wheel back in 2012. The shop pulled the tranny out to do the work. After reinstalling everything I noticed a slight hesitation when shifting from Park into drive (3) but only on the first start up in the morning. It was only about a one second pause. The rest of the day the car would shift normally from Park to (3) without hesitation. Over the past year the hesitation continued to lengthen until I finally started shifting from Park into low gear (2) which would shift quickly then I would shift into (3). The tranny fluid level is correct -checked when engine is at operating temp and after shifting thru all gears. I have changed to tranny fluid and filter several times - no sludge or metal shavings in the fluid. I always use the correct filter, not the aftermarket one.
When the hesitation started getting longer even in (2) I got panicky. I had the shop change the Vacuum Modulator and rubber hose - didn't solve anything. It still shifts correctly the rest of the day. It only hesitates on the first shift of the day (or after the car has sat for a long time - more than 6 hours or so)
Has anybody heard of these symptoms before. It seem related to the fluid settling overnight and having to be recirculated in the morning. Is this a pump problem? I have no idea how the pump works on a tranny - is it part of the torque converter? Could it have been damaged when the tranny was remounted after the work in 2012?

 

[stingrayl82]

My '82 L-83 did the same thing; the pump was shot.

 

[A1Avette79]

My '82 L-83 did the same thing; the pump was shot.

I'm afraid to ask - what was the repair $$$$

 

[stingrayl82]

I was lucky enough to have a 700R4 from a '93 Camaro, which cost me $500. All I had to do was swap out the valve body, so that the harness would work.

I did end up having the original 700R4 rebuilt and stuffed into my '79 L-82....IIRC, it cost me $1100 for the complete R&R....taking out the old TH350, rebuilding the 700R4, shortening the drive shaft, and putting it together.....that was in 1999 or 2000.

 

[A1Avette79]

I was lucky enough to have a 700R4 from a '93 Camaro, which cost me $500. All I had to do was swap out the valve body, so that the harness would work.

I did end up having the original 700R4 rebuilt and stuffed into my '79 L-82....IIRC, it cost me $1100 for the complete R&R....taking out the old TH350, rebuilding the 700R4, shortening the drive shaft, and putting it together.....that was in 1999 or 2000.

Is the pump in the Torque Converter?

 

[stingrayl82]

Is the pump in the Torque Converter?

No, the pump is the first thing you see, when you take the torque converter off the transmission.

Here's a pic.

 

[stingrayl82]

Also, not a big thing, but you don't have a flywheel, you have a flex plate....flywheels are for manuals.

 

[A1Avette79]

Also, not a big thing, but you don't have a flywheel, you have a flex plate....flywheels are for manuals.

Ya I kept saying that to the mechanic and he kept correctly me. Old habits...

Was changing the pump a big job? I've done a bunch of internet searches for transmission pumps but no results come up. Are they available?

 

[A1Avette79]

Also, not a big thing, but you don't have a flywheel, you have a flex plate....flywheels are for manuals.

I see your note about your old vette you sold. If you know a cop have him run the VIN. Maybe the owner will sell it back to you.

 

[stingrayl82]

I didn't do any of the work on the '79, all I did was the valve body on the '82.

The last time I rebuilt a TH350 was in '95 and it was very easy, using a rebuild book that had step by step pictures.

Parts should be very easy to come by.

http://www.summitracing.com/parts/tci-313400?seid=srese1&gclid=CP2hsrDK_b8CFSxk7AodwFEABQ

 

[stingrayl82]

I see your note about your old vette you sold. If you know a cop have him run the VIN. Maybe the owner will sell it back to you.

I have a friend, who is a State Trooper, but she will not tell me anything, other than the fact that the car is in Texas....something about privacy issues.

 

[stingrayl82]

It might be cheaper just to get a new TH350 and save yourself the headache.

JEGS Performance Products 60300 JEGS Performance Transmissions - Free Shipping on All Orders @ JEGS

 

[A1Avette79]

It might be cheaper just to get a new TH350 and save yourself the headache.

JEGS Performance Products 60300 JEGS Performance Transmissions - Free Shipping on All Orders @ JEGS

Ya I wish I could afford a new tranny. Unfortunately I have to keep patching this car together to keep it on the road. Its my only transportation right now.

Thanks for all the info tonight. Its been really helpful. I have an early morning - gotta turn in now. Give my best to the Lone Star state from an old Aggie. I've been in Miami for 21 years and I still can't get used to the people here. Nothing like the friends I have in Texas.

 

[stingrayl82]

Ya I wish I could afford a new tranny. Unfortunately I have to keep patching this car together to keep it on the road. Its my only transportation right now.

Thanks for all the info tonight. Its been really helpful. I have an early morning - gotta turn in now. Give my best to the Lone Star state from an old Aggie. I've been in Miami for 21 years and I still can't get used to the people here. Nothing like the friends I have in Texas.

No worries. Have a good night.


Gig 'em!

 

[Antz81]

HammerDown has rebuilt his TH350 very recently. He may be able to give you some ideas or tips to help you out on this.
Good luck.