1972 Cutlass 350 finally started and runs great in the garage.

Rebuilt BOP TH350 transmission and installed 2800 stall converter (rebuild and converter about 10 years ago, but has not been moved).

Filled transmission full to dipstick mark when engine is warm and at idle (took another 6 quarts). Put around 4 quarts in at installation 10 years ago. Cannot remember if I put fluid in the converter, but I like to think I would have.

Pulled cooler line to verify that pump is moving fluid. It definitely is!

Checked linkage to verify shift position. Good as well.

Issue is that when I shift into Drive there is definite engagement, but the car just won't take off when I throttle. Same for reverse.

I have never lifted the rear wheels off the ground and let them spin?

Willing to take to transmission shop if required, but I don't want to.

Any ideas-suggestions???

 

Maybe the converter is bad

 

Oops, sorry I said 2800. It is a 2400-2600 rpm flash stall 240900 TCI Breakaway Torque Converter. Purchased and installed new 10 years ago. Engine started on frame, but car was never driven.

TCI 328800 TCI Pro Super Transmission Kit

 

Not sure what you just said.
You either did or you did not fill the TC ten years ago. If you did not, the tangs may have broken - let's hope you did fill the TC (but, when you say you cannot remember - it's confusing). "If" you put 4 qts. in the TQ & added another 6 qts. @ warm/idle that would be the correct capacity of 10 qts. If you've validated you're getting flow, as you said, it sounds like there still isn't enough trans. fluid (first guess). You did put the Automatic Transmission Modulator back in the transmission and hooked it to vacuum? While it tells the transmission what kind of load is being put on it (while you're driving), allowing the transmission to react with the proper line pressures and shift points, it may or may not influence what's happening with your transmission after having sat such a long time?

 

My logic in suggesting you're still low on trans. fluid is this. You rebuilt the trans 10 yrs ago, it sat for 10 yrs during this time it was never tested. Did you fill the TC or not (as you suggested you'd like to think you did). Now, 10 yrs later, you run the engine, warm the fluid and at idle you installed an additional 6 qts. (bringing the capacity to the correct 10 qts) - "if" you actually did fill the TC 10 yrs ago w/ 4 qts of fluid. Let's say you did not, or your numbers are off, "if" you had a large pocket(s) of air (sitting for 10 yrs) and just now installed an additional 6 qts fluid, you may be far below the capacity you think you have in the system - in particular if you had/have a large air pocket(s) in the system. Could be the system is getting air bombed - no fluid, lots of air. If it were me, I'd raise the entire car on 4 jack stands. I'd allow the engine to run for a good 15 minutes check the trans fluid level. Engage the trans (while on 4 jack stands) - increase/decrease/increase/decrease RPM while in gear - for numerous cycles. If it's an air bomb, increasing/decreasing RPM while in gear could remove air pockets in the system. Continually check trans. fluid level repeating often.

 

I will set the car on jack stands and attempt to get air out of system and adding more fluid per recommendation.

I was told by a shop that sitting for that long may have dried out the seals and frictions. Just do not want to burn up anything. Maybe too late now. Any tell-tale signs?

I apologize buy I can't remember how much fluid was initially put into transmission/converter.

 

If your dip stick reading is full, when warm, there’s fluid in the system - how much right now is questionable (if there are air pockets). You’ve already reached a tell-tale sign - will not go into gear (evidently). Better to error on an overfill condition than a dry condition as excess will bleed from vent hole.

 

The shop is probably correct. Was it a transmission shop ?

 

No and gentleman had not worked on one for 30 years.

 

Wouldn't it make sense to ask a transmission shop ?

 

Ok, just back in from garage.

Set car up on blocks at frame. Car is level. Rear end blocked up as well.

Warmed engine and shifted through gears many times remembering to brake between.

Tires spun hard and seemed to speed in forward gears, but spun inconsistent I reverse. Sometimes tires came to a stop in reverse until I put it in park or neutral and shifted back into reverse. Again inconsistent in reverse.

Fluid did not move on dipstick. Haven't set car back onto floor since I still have inconsistent reverse.

 

As I stated in my previous thread:

Increasing/Decreasing RPM is what is important - you said you shifted through gears many times. If you did it at idle - it basically did nothing to remove any air pockets. The transmission wants to see a "load", you have no load at idle. And, yeah, you obviously have to hit the brakes if you're going between drive & reverse. Not sure I should state it again - you need to INCREASE & DECREASE the RPM - it does nothing at idle.

 

Will do

 

Don't be afraid to brake torque it a bit if you like. I mean don't go nuts. Don't be afraid to increase RPM to 2500 or 3000 then decrease, then increase, etc. Finally, outside of taking/talking to a trans. shop as has been suggested, I would definitely open the transmission and examine the state of the transmission filter to see if it's clogged or whatever.

 

Any shop worth a quart of trans fluid will cost the bearings/thrust washers and transmission seals with some kind of assembly lube. Assuming the transmission clutch packs air checked good during the original assembly, the seals will be fine now.

It normally takes some heat over a long period of time to make the rubber seals hard.

Will the car roll normally when it’s not in park?

Get the tires off the ground, see if they move. Depending on the converter, it might take some throttle to get the car to move. The fact that you say you can feel the trans go into gear suggests something is happening with the clutch packs.

 

Once you've lowered the car back onto the ground (I'd still check the trans filter), get it into a position where you can drive forward down the street/road - don't worry about reverse. You may find it takes a significant increase in RPM before it begins to move forward, but I feel confident once you get it under load back on the ground with enough RPM she'll come back to life. Good luck!

 

Put back down on ground.
Reverse still very questionable.
Drive and 2nd try.
I think low is there and solid.

Is there any way to verify fluid level besides dipstick?
I do not trust dipstick or tube as neither are mated to this vehicle.

 

Answer is no. You have to have the correct dipstick. Say you didn’t have one - at all, you’re in the middle of nowhere (Mojave Desert). Keep filling it until it pukes out the vent hole. Better to error on the side of too much than not enough. Install the correct dipstick and tube.

 

I will put in a quart at a time and search for a new tube and dipstick.

 

The full mark will be pretty close to the case/pan parting line. Unfortunately, the only way to verify that with any accuracy is to drop the oil pan.

 

Was able to drive 1/2 mile down the road in low no slips.

Shifts into 2nd, but not solid.

Definitely slips in Drive.

Reverse slips so bad pretty much non-existent.

 

Start adding ATF as you previously suggested - one quart at a time. Slippage is one of the most common signs of low ATF, so is delayed gear engagement. Trans needs significant hydraulic pressure. No/Low ATF = no/low hydraulic pressure. Start filling w/ ATF.

 

If a hydraulic pump isn't working you take its blood pressure to verify its health. In a transmission, this is called line pressure.

Get a 300 PSI hydraulic trans line pressure gauge. Screw it into the test port. Look up a TH350 line pressure specs, and see where it is.
Each position (of the shift lever) has a specified pressure range.

Bad line pressure means time to take it apart and see what failed.

One possibility is if the converter wasn't seated into the pump during installation it damaged the pump.

 

Drove 50 miles yesterday.
Each time shifted directly into low. Engaged immediately, but took 2-3 seconds to catch.

Low solid with hard shift every time into 2nd. Also hard downshift after 2-3 seconds back into low when manually shifting. Doesn't downshift by itself.

From there not solid in 2nd unless I stepped on the throttle, then normal quick response of increase in speed. But never a shift into drive when manually shifting only increase in rpm. Constant slip when manually shifting from 2nd to drive.

Still no reverse.

Lifting car and dropping pan today to drain overnight. New filter, gaskets, dipstick tube, and dipstick tomorrow.

Also new o-ring for detent cable to stop leak. That cable leaks alot with the car just setting overnight. That makes me think fluid level is above pan? Hmmm?

 

Transmission had approximately 50 miles on fresh unprofessional rebuild (me). Upon dropping pan... I found a small amount of slimy deposit at wire filter and zero metal in pan. Replaced metal filter with a finer dacron style. Fluid smelled fresh and not burnt.

Still only low.
Will shift hard into 2nd, then slipping unless solid throttle. Speed climbs with RPM.

Slips in drive.

No reverse.

Basically the same as before Fluid/ Filter change.

Giving up

Appointment to have Transmission dropped and rebuilt Tuesday.

 

Check your vacuum modulator and vacuum line from the manifold. Sounds like no vacuum to modulator or bad one.