If you've had a transmission rebuilt, how long did they last? Im on my third rebuild. The origional lasted 110,000 miles, the second died under three years and the last one I had lasted one year... Why doesn't a rebuild last 70+ miles? No im not beating on the tranny either.
Is it possible factors outside the transmission could contribute to an early demise?

 

wow..... the trans in my chev truck went near 170,000 miles after a rebuild in 1989. Several different motors in the truck. Mild 350 to a current ZZ4 motor.

It was just rebuilt a few weeks ago, hopefully for another 170k miles.

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"If it ain't broke.... get out the tool box"

 

It's not so much as whether a rebuild lasts as long or is as strong.... ummm what i'm trying to say is...

Most 'rebuilds' are done half-assed and basically involve just changing out the frictions and re-using all the partially worn out parts, so therefore, in theory it should not last too long.

A good rebuild replaces all the wear parts, frictions, steels and the rubber seals which are usually neglected, along with all the bushings and torrington thrust washers... basically anything that moves and everything that seals the fluids, including all the 'forgotten' parts like the 3rd accumulator check ball capsule. Can you imagine how many times that ball accelerates and slams into that very thin steel 'seat'. If this leaks, it burns the 3-4 clutch pack out in short time. A simple couple dollar part, and is usually neglected in a simple rebuild, along with the pump, "if it was working before why bother it".... why not get a rebuild kit for it, it's the heart of the trans and usually neglected.

Then there's a true high quality, high performance rebuild which involves the above, plus using much higher quality parts like borg warner, alto red eagles, ect... and recalibrating the valve body, changing fluid pressures and flow rates for a firmer WOT shift without being overly harsh, adding a Sonnax checkball, basically fixing all the well known problems with the stocktrans, adding vette servo, enlarging the front drainback passage, adding a dual slide spring, changing the governor gear.... all the little things

So basically a rebuild could be alot better and last alot longer, under more hp, than a brand new one, so it comes down to who rebuilds it, and what they consider a 'rebuild'. Personally I consider a good rebuild a 'remanufacture' with the best parts and someone who stands behind their work.

 

This is an interesting question and involves some things that many don't take into account.

When a tranny is brand new, everything seals perfectly, the pump has just the right clearance, there are no leaks internally, etc, etc.

Now consider the life of a tranny. It's job is to manage TORQUE, PLUS it goes through thousands of hot and cold cycles which also leads to warpage, not to mention the normal wear that takes place. Add to this that it's life blood, ATF, runs under pressure, sometimes as high as 300+, and did I mention heat? Also, the engine when new is tighter than a 70K engine and if you were to check it with a torque wrench you would see that it takes allot less torque to turn that broken in engine and that extra torque that WAS used to turn things is now available to load the tranny harder than when new. Add all this up and you find that just replacing the normal wear parts in a tranny often doesn't yield a tranny that lasts even half as long as the original did. In fact, if you COULD get a 'new' tranny (you can't, even from the dealer, they are remaned by minimum wage people who don't know how a tranny works and don't have to for that matter) IT wouldn't last the same as the original due to the changes in the engine referred to and I haven't even mentioned modified engines.

On top of this are the built in weak points of any given tranny and I think you are getting the picture now. Here's another dirty little secret about the tranny business; I have know many guys who have been 'assembling' trannies for years and couldn't tell you for example, what is applied in a given gear range or what normal pressures should be in that tranny. This means that they can build plenty of trannies, often very fast (Bosses like that) but when there is trouble you get allot of blank expressions much like the deer in the headlights look (Bosses DON'T like that).

What to do? Well, as you now know, you can not get a NEW tranny so all are used or 'rebuilt'. The secret is to find someone who nows how to FIX the 'age' caused problems along with the inherent design flaws in a given tranny. Much of this, IMHO, is FIXED with the use of a TransGo Shift Kit and I am not afraid to give away one of my big secrets of success because as you may know, just giving someone your mothers secret pie recipe will not allow just anyone to duplicate the same flavor. Somehow it just isn't the same. So is it with tranny building. You still have to be talented to do it right but it helps if you have the right recipe anyway!



[This message has been edited by transfixleo (edited September 23, 2001).]

 

I had AAction Transmissions did the rebuild in 4/26/00 and a year later, the reverse stopped working on it. I was told that the torq converter broke apart and started sending shavings into the tranny. AAction said since it was just over the warrenty by about 1000 miles, the gave me a "deal" and did the rebuild for just under 800.00. This time it only had a 6 month warranty and by the way it feels, I think it's gonna go in less than a year again. 1st through 3rd shifts like a champ, however overdrive almost feels like it bounces 2 or 3 times before it smoothes out.

Anyways, who would you recommend I go to have a tranny redone? I live in South Florida.

[This message has been edited by ChrisH (edited September 23, 2001).]

 

I know a guy in Tampa I would trust. He owns a shop named Transmission Physicians and his name is Fernando.