smyth1

been looking through the shop manuals on rebuiling the trans.how hard is it to do and or get the parts to do it myself?not much experience with autos but have done a few m 21 4 speeds and a trans for my dirt sportsman car.pretty good at rebuiling gearcases for the raceboat as well.may be it's time to figure out the mystery of these things.

borland

Rob Edwards

On a scale of 1-10,

Gregg K

I feel it's cost effective to let the pro do it.

I've rebuilt a lot of manual trannies. They were mostly trivial. However, there was an early Honda Civic that I had to pull three times because of it's quirks.

When I was a kid, I had a friend who rebuilt autos for a living. If I recall, there are two levels of rebuilding them. One is to replace whole assemblies. The other is to do every little bit. One is pretty easy, the other takes test benches and equipment.

Sometimes just paying the money is easier than learning the hard way. And there's a pretty good chance that's the way one would learn it the first time doing it.

I'd love to hear that I'm full of it. Maybe it's easier than I'm thinking.

pcar928fan

The shop that works on my 928's did 1 once...and I was told that would be the last one! It was not one of mine but apparently it was a HUGE and frustrating job!

Tails

It was designed by a person, it was assembled by a person, so it can be rebuilt by a person.

The skill, competency and confidence levels need to be pretty good and if you do a web search you can fine some very good instruction for the MB 722.3 boxes, as well as there is an instruction manual in Jim Moorehouse's Technical CD and the WSM has a very comprehensive set of instructions.

The most difficult part is the valve body, lots of small parts etc., and they can be easily lost.

You will need a comprehensive set of tools, including torque wrenches and a very clean working environment.

Auto boxes are not a "black art".

If you do a search you should find so good information on repair etc for auto boxes.

Tails 1990 928S4 Auto

smyth1

doesn't look too bad to me.getting parts could be another issue in itself

Rob Edwards

I don't understand how an automatic transmission works, let alone understanding how to fix one, so I'm irrationally intimidated by the thought. OTOH, if you have a broken tranny and a dead car, there's little downside to trying, except for time and money. Please take and post lots of pictures, it would be a very informative thread, if only to serve as a warning to others.

Randy V

Take lots of pics then post the procedure here.

Cosmo Kramer

There was someone on here that was going to rebuild his own auto and was documenting it along the way. He ended up giving up when he had it apart and didn't take it any further.

danglerb

If you have a lot of experience repairing both watches and forklifts, should be no problem. Otherwise find a shop that does a lot of Mercedes Benz automatic transmissions, the 928 is a minor variation on some middle 80's MB sedan.

Personally I would take one of two paths;

Cheap
Find a used transmission that came out of a running car with no transmission issues. Until messed up from old/low fluid these AT are very robust. 928Intl should be fine.

Keeper
Your not that far from Steve Catteano, have him rebuild your AT.

smyth1

yes,talked to steve a time or two thus far.going to take it out of the car tomm.probably take it apart then decide at that point which route to go.

soontobered84

+1 My thoughts exactly! If I absolutely had to, I probably could do it, but the irrational fear and intimidation of it would preclude me from starting on it until absolutely necessary.

Leon Speed

So what exactly are you looking to rebuild?

smyth1

getting alot of people who are saying that.machines don't really scare me.just have to figure out how they work.i'm an electrical mechanical contractor by trade.