I'd appreciate any advice from experts.

I have a 1976 A904-LA torqueflite with a "non lock up" converter behind a 318 V8 1976 Dart that I am trying to keep alive after quite a long garage sleeping (15 years).

The question is about slipage. This was my 1st set of wheels and my 1st torqueflite and the only complaint I had from the time I was driving it is that it sounds like slipping a bit when climbing a steep street (any gear) and when driving on the highway in 3rd gear it will show a higher RPM when the car is going uphill (for the same speed). The rpm increase is about 250 RPM for the same speed and always consistent:

In 3dr gear:
At 40 MPH it shows 2000 rpm and 2250 rpm to keep speed when on a steep road
At 60 MPH it shows 2500 rpm and 2750 rpm to maintain same speed driving uphill

The car is fast and does not appear to slip when in 1st, D or reverse if step on gas, tires smoke instantly.

Question is, the lock-up converter came to eliminate some TC slipage but how much slipage is normal on old non lock-up units?
Would a stall test tell me if the tranny (clutches and/or bands) is slipping? Can I do the stall test on reverse to check front clutch and rear band?

I've just finished doing some VB cleaning and installing a new TFSC shift kit, new filter and had the opportunity to check bands that for my total surprise were in great condition (rear band has never been adjusted and took less than 1 turn to adjust to spec, same for the front band, which might have been previously adjusted), drums look good.
I found some substantial amount of particles in the pan under the filter (stock pan did not have a magnet). I am quite sure the tranny has never been serviced. Pics at the end.

I am still in the process of filling it up with fluid and road testing.

I might have some other issues on my transmission such as leacky seals, worn frictions but how much rpm increase is normal for a non lock up TC on the road?

Some pictures:

http://imageshack.com/i/ex1DZ5zhj

http://imageshack.com/i/idNhggqtj

http://imageshack.com/i/idRBwSw4j

http://imageshack.com/i/f0s7g0thj

http://imageshack.com/i/f0oAsk2Mj

http://imageshack.com/i/exOArv4sj

http://imageshack.com/i/kq50SxePj

http://imageshack.com/i/p4gVUOimj

http://imageshack.com/i/iqvKlGTFj

http://imageshack.com/i/f0TUly9xj

http://imageshack.com/i/f0KuBwtRj

Thanks in advance !

 

Just depends on the amount of stall was built into the converter when it was new?? It could be a problem with the blades in the converter might be bent or loose. So with out opening it and testing it, You really just dont know.

 

here is an EXTERANL filter i found.
use ONLY steel brake lines, for coolant lines. copper WILL break off. the factory uses steel for a reason!!!! mopar most use 3/8 dia tube, but some might be 5/16. i think most have the fluid in at the rear left side. here is an EXTERANL filter, i found. have one on my 01 dak. my idea is when you put a new filter in side this one will help from having to do the inside one as often.*
the old auto zone 2210 magenfine filter is no longer available at auto zone. BUT i did find the same thing as JX-160 brand-- ATP. at a real parts house uses 3/8" tube. a JX-150 for 5/16 tube. ONLY use high pressure hose. If you must. SAE J1019 217 psi working. NOT fuel hose for a carb engine.

 

Thanks for the input, my concern would be having slipage on clutches and bands so I figure the stall test would tell me if anything slips @ WOT but I never did it before.
I`ll finish changing the rear seal this weekend and take it for a ride then if everything is ok I`ll try the stall test.

 

As others said, if this is a non-stock converter, it can have substantial slippage. In fact, if your car has highway gears and you can spin the tires with the 318, it is very likely that you have a high stall converter. You may want to try the stationary transmission loading test, and see what your stall speed is (assuming the rest of the transmission does not slip, and of course, we do not know that yet).


On my 440, which does have stock converter, as soon as you reached 3000 rpm, the converter slippage is more or less negligible. At WOT, may be you can see 100 rpm difference from cruising. At 4,000 rpm, even at WOT it would be almost completely negligible. But at 1500 rpm on 3rd gear (about 45) you can easily see 200 or even 300 rpm as you accelerate, with may be 7-5 in vacuum.

 

They had both a hi and low stall converter available depending on application

 

Thanks for the information demetri.

The transmission and the torque converter are 100% stock from 1976 and came with the car. The stall speed as per the manual is 1900 - 2100 rpm.

I never ran a stall test and the car has been in the garage for years.

If you hit the gas 1/2 way the car will smoke tires and it pulls good.

You said that at 4,000 rpm, even at WOT it would be almost completely negligible. But at 1500 rpm on 3rd gear (about 45) you can easily see 200 or even 300 rpm as you accelerate, with may be 7-5 in vacuum,

Question, if you are cruising in 3rd gear about 45 mph and then start going uphill the rpm increase will show constant until you get to the top of the hill or the rpm increase is only seen when you accelerate?

I have only tested the car at speeds from 40 to 65 mph and driving uphill at that speed will show 250 rpm more than on a level road.

If I understand well the non lock up converter does slip more until certain speed and/or throttle position/pressure is reached and then the slipage becomes negligible.

I need to finish installing a new rear seal and will run a test drive for more info. Maybe the new filter/fluid + transgo TFSC and a bit higher line pressure would change something.

 

Whether you are accelerating or going up the hill, it is really the same thing, the converter does not know it. But yes, if you try to maintain speed throughout your hill climb, at the steep part of the hill the rpm will increase some, and when you reach the top and back off the gas, the rpm returns to where it was. The 1500 rpm is not a good point to climb steep hills with non-lockup. If possible, when I see a steep hill like that, I try to accelerate and take the hill at higher speed, you use less gas, and put less heat in the transmission.


Yes, at higher speeds, the slippage will become negligible. The torque converter transfers torque via the momentum of the fluid from one rotor to the other. It is the relative speed of the two vanes that generates torque. When both input and output vanes spin faster, they need less relative speed to transfer the same torque.


The lockup converter gives very small benefit, unless you start having "performance" converters (I have it in quotes, because I see them as poor performance). Then, when you have a lockup clutch, you can have a high stall converter without the serious consequences of the high slippage.

 

Ok, I just wanted to let other people who may be interested in the subject know that I thought I had substantial damage on my torqueflite due to the amount of particles in the bottom of the pan, check pics:

http://imageshack.com/i/ex1DZ5zhj

It is the residue from just about 85,000 miles driven in the first 8 years or so. The tranny is 38 yo now.

Pic below shows residue pulled to 1 pile in the pan:

http://imageshack.com/i/idNhggqtj

Looks bad but the bands were not far from spec for my surprise, perhaps 3/4 turn to adjust.

I did install the Transgo TFSC kit while cleaning the valve body real good but I could not feel much difference at all.

http://imageshack.com/i/p4gVUOimj

After replacing the rear and manual shaft seals, new filter, new pan magnets and gasket I filled her up with dexron II and it drove perfect, just like before in the old days.

http://imageshack.com/i/f0KuBwtRj

http://imageshack.com/i/f0TUly9xj

The 1-2 shift became a bit quicker and harder in some occasions (I did not like the change), hope the kit does anything to overall preserve the tranny.

The stall speed is a solid 2,400 rpm hot and cold, D, R and 1. Book sais 2000 to 2200 rpm (A904-LA).

The rpm increase I experienced on the highway in 3rd gear seems to be due to the non lock-up TC more than anything.

I am happy with the results but the only change may be knowing it is much cleaner inside and not leaking in the garage anymore.

 

Sounds like good progress........ That kit is just the improver kit...
Glad it Drives a little Better...... I would have used just plan F-Type Fluid... But that would have made it a little firmer.....
Keep up posted on how it settles in....

 

Type F never made to where I live, even the old C4`s used Type A and later on, dexron. Dexron II is still being made in Brazil and costs only about US$ 8.00/quart. I imported 14 quarts of ATF+4 for my 46RE and cost me around US$ 35.00/quart!

Here is an interesting video from the 70`s when Chrysler recommended dexron, I hope dexron II won`t do anything bad for my old Torqueflite, thanks for the input.