What about high-mileage ATF?

Pfft. When did 75k start being "high" mileage?

DS

My perspective as an experienced Amsoil Inc. Dealer: You can't go wrong by using the best that money can buy; it doesn't cost it pays in more ways than one. When you compare brands, price is not necessarily the main factor. I figure that if your engine and drive train is tight and is in good running order, give the brand that has the best stats. RH.

I do have a transmission leak. Not sure where from since I can't put it up and look. This is a 20-year-old van whose book value is prob. less than $1000, but only has 87,000 miles on it. I know you guys don't like transmission additives/sealants, but I'm tempted to try something like Gunk Transmission Sealer or Lucas Transmission Fix (the Lucas is said to contain no solvents). If I can buy some time, I don't mind adding fluid periodically. If the transmission were to go out, I wouldn't have it fixed on this age/value vehicle. I'd sell it to salvage or an individual, or donate it to charity. If it were something as simple as a pan gasket leak, I might have my mechanic fix that next time it's in for something else (it's a $40 taxi ride to leave the vehicle). I think I'll try the Lucas; if it doesn't work it'll just eventually drip out :) Comments appreciated or other product recommendations.

GS

I have used "transmission conditioners" in older/higher mileage vehicles auto trannies many times and they have never hurt and often helped the shift quality of the transmission and reduced leakage. Just stick with a name brand and I doubt you'll have any problems. All they do is soften and swell the rubber seals a bit to make them seal better.

Transmission

A tablespoon of brake fluid will do the same.

What type van, what type transmission? A number of transmissions tend to develop leaks at places like the seal around the gear selector lever, the seal around the kickdown lever (or cable lever) and the speedometer pinion adaptor. Those seals cost on the order of ~$5.00 and can be replaced with the transmission in the car. Hardly worth risking damaging all the OTHER seals (including the input and output shaft seals and all the internal servo seals) with "seal sweller" additives when the fix is so easy.

'84 Dodge Ram van, full size V8, automatic. 87,000 miles. A seal may be $5.00, but labor would make it a little more costly, since I can't do it myself. I could have someone glance at it next time it's in the shop for something, but I won't let anyone pull the transmission regardless in this 20-year-old vehicle--labor would probably exceed the book value. Thanks.

GS

BINGO! That's exactly the transmission I was suspecting.

A seal may be $5.00,

Absolutely NO need to remove the whole transmission!

A lot of people replace those two seals without even dropping the trans pan, but I find that the easiest way is to open up the pan (like when you're going to do a fluid change). It really is easy, and even if you don't want to try it yourself you should be able to find SOME mom-and-pop transmission shop that will do it out the door for well less than what the van is worth.

Basic directions:

Raise the car securely, all that safety stuff :-)

After dropping the pain and draining the fluid, remove the gear-selector lever and the kickdown linkage from the little shafts that go into the transmission on the driver's side top, just above the pan/case gasket.

Inside the pan area, un-bolt the 10 bolts that hold the valve body in the transmission. Gently start to lower the valve body. You'll find a bar continuing to try to hold it in- this is the parking pawl linkage. Disconnect the "E-clip" that holds it to the valve body, and remove the valve body from the transmission leaving the linkage up in the tranny. Pick up the great big accumulator spring that fell out when you weren't looking :-) Don't worry, it goes in the ONE hole big enough to hold it, so you can't mess up. And the trans will work fine even without it, the feel of the upshift will just be slightly firmer. Keep the valve body CLEAN!

The outer seal is in the top of the transmission case where the shaft on the valve-body went through. Pop it out with a screwdriver, and press the new seal in (from the top) with a C-clamp and a couple of large socket wrenches.

The inner seal came out with the valve body- the kickdown shaft passes through the center of the gear select shaft and is held from above by an other E-clip. Pop off the E-clip, and remove the washer under the E-clip- now you're looking at the rubber seal between the two shafts. Dig it out with a small screwdriver, and install new one. Re-install washer and E-clip.

Re-install valve-body, making sure to put the accumulator spring back in its place and to engage the parking link and re-install that E-clip.

Re-install shift and kickdown levers on outside of trans.

Put on a new filter, re-install the pan, and fill with fluid.

Thanks for all the details. I'll print it out and show it to my mechanic. Thanks.

GS

My folks once had a car that we used at least a pint of brake fluid in the AT on the recommendation of an old auto mechanic they knew. Didn't hurt the AT any but didn't stop the leak either - I think it was just too far gone.

I believe the brake fluid causes the seals to swell slightly, it's not really a fix, sort of a band aid that sometimes works.

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