trany slipping why?

[z26 crazy]

my tranny slips only when you step on it why?I've changed my fluid and filter and I added lusas renew worn trannies.It didn't help at all. I've been driving it like this for 7mths.can u tell me is it something that is easy to fix or not?

[jsgold]

Most likely your clutches are worn out. Very little friction material left on them. Lucas stuff won't do any good once it gets to a point. You could take it for a once over at a good transmission shop. They should be able to tell and give you an estimate, but most likely a major overhaul is due. I would not work on a transmission myself unless it was a filter change, fluid change etc.

[silicon212]

First thing, check your fluid level! More than half of transmission "failures" are due to a low fluid level condition.

[z26 crazy]

is there clutches in automatic transmissions? i though there is only bands in them.

[silicon212]

Originally Posted by z26 crazy

is there clutches in automatic transmissions? i though there is only bands in them.

There are clutches and bands. Generally, one or two bands and and up to 6 clutches. The clutches have stacks of anywhere from 3 to 6 and more alternating steel and friction plates. I'm not entirely familiar with the transmission in your car, which should be a Turbo HydraMatic 4T40.

[Blue Bowtie]

Another step to possibly solving the problem is to drain all the fluid out and refill it with REAL transmisison oil. Don't add anything like "Trans Medic" or "Lucas Band-Aid Trans Fix" since they rarely do anything except take money out of your pocket and put it into the coffers of these companies.

Check line pressure to see if the hydraulics are adequate to actually hold those clutches and bands effectively. BTW - The more you drive it in "slip mode" the more damage you may be doing. What may have started as a simple trans oil pressure modulator or regulator valve problem could result in a total rebuild.

[richtazz]

I have to disagee Blue. Adding all new trans fluid to a high mileage (over 80k) trans is a BAD idea. If the fluid is so bad/burnt that new fluid is needed, it's too late. The new fluid is grippier than the old, and will cause catastophic failure of the clutches 90% of the time this is done. Fluid exchanges are for low mileage cars and only recommended if done regularly. Lucas and Trans-medic are additives that will help with a sticky valve, but I agree they won't fix an abused transmission. I would recommend doing a trans filter service and only replace the fluid lost when dropping the pan.

[Blue Bowtie]

Rich,

I think we're saying the same thing. Drop the pan to get as much of the additive out as possible, replace the filter pad, and refill. There should be enough of the leftover friction material in the 7-8 quarts in the converter to maintain friction if there is a problem with the wear/friction surfaces. To me, it's better than leaving the sludge from the additive in there. And we really don't know hte mileage, since it was never stated, but having driven it 7 months in that mode may have already toasted the soft parts. The only saving grace is that it's a light vehicle and may not have done a lot of damage, but in 7 months...

I've changed fluid in a transmission or twop with over 100K and had no problems. However, once problems start to occur, you're right in that changing the fluid might be the LAST thing you want to do. As a "band-aid" fix you can always add some of the old Type F trans oil, since it doesn't kubricate as well as Dexron, but that doesn't always work either. This one may already be too far gone.

The line pressure test should help indicate whether the problem is due to hydraulics or friction surfaces.

As Silicon indicated, proper oil level is important. High level can be just as detrimental as low level.

[richtazz]

Well put Blue, and thanks for the clarification as to what you were saying. I thought you were recommending a trans fluid exchange proceedure, which I strongly recommend against on a high mileage or troublesome trans.