beccaris

has anyone out there used a transmission oil additive? i have a 85s 4 spd which has an oil leak around the torque converter area and i was going to use some form of additive to try and reduce the leak, but i dont want to shorten the life of the transmission. any advice?. the other question i have is what is the lifespan of the 4spd auto in general?.my 85s has 180000km on it and it still shifts ok.i use mineral transmission oil.

Mrmerlin

If your trans is leaking the best way to fix it is pull it an replace the front Pump O ring and the torque converter front seal, if you do this make sure that you put some grease on the bushing just inside the front pump where the rear snout for the torque coverter rides this prevents it from seizing. And also you can RnR the torquetube, and the torque converter front bearings, I dont know what you mean by mineral oil but i believe that you should be using Dextron 3, I wouldnt add any seal swell as they probably wont work and may damage the transmission, and depending on the how much its leaking it may be easier to just add fluid till you repair it properly

Mark

I THINK he is referring to non-synthetic...

Bill Ball

I have no problem with throwing a bottle of Trans-X or your favorite trans cleaner/seal treatment into the tranny. I have used such to resolve a sticky 1-2 shift valve (tranny would not drop into first) and it worked. I've gone another 60k miles since with no other problems. If you have no other reason to pull the torque tube then go ahead and try it. It may not stop the drip, but it will not hurt anything.

There is no good answer to the lifespan question. I'm at 184k miles and still going strong. Many get beyond 200k miles on original trannies, others need a rebuild at less than 150K miles. Until you start having shift problems just keep enjoying the car as it is. Change the tranny fluid like religion at 30k mile intervals. Besides that, just make sure the level is correct, using the warm level lines.

ZEUS+

I agree with Bill. Have used trans-x numerous times with success. If it is necessary to replace front pump seal, dont remove pump if o-ring seal is not leaking. Use trans fluid to lubricate seals. Torque converter is what drives pump and is well lubricated. Only use a petroleum jelly like vasoline in an automatic trans when necessary for certain assembly procedures. It liquifies quickly with no adverse effects. Grease can withstand higher temps and could possibly restsrict a passage.

IcemanG17

The Mercedes trannies in 928's are very robust......remember they were originally designed to propel cars weighing at least 1000 lbs more than 928's with similar power levels.....& for a very long time too....so in a lighter car....they last even longer!

Steve Cannteo (misspelled) is the resident rennlist tranny expert..... He works on them everyday!! He should have a good answer

beccaris

thanks for the input.will be doing a transmission service shortly with mineral based oil( non synthetic).by the way i'm located in sydney australia.

Brian Felts

If you can get your hands on Lucas products, their trans additive is the best in my opinion. I use all of their products and have nothing but good to say about them.


Brian

Podguy

I had a leaky front seal and put in some trans-X. Two weeks later the transmission started to sllip badly and making a loud scraping sound.

Now maybe it was just a coincidence But the front seal was only dripping and showed no drop in fluid over 2000 miles. In fact, it was the best shifting transmission I have seen in a 928.

I was figuring that I would try it and if it did not work I would just pull the transmission and replace the seal. Now I have to rebuild the entire transmission.

Would I try it again - no way.

Dan the Pod Guy