1989 190E 2.6 B3 Replacement Question - PeachParts Mercedes-Benz Forum

the tenor man · #1 06-03-2009, 09:38 AM

Hello all,

I have a 1989 190E 2.6 that has a faulty reverse...I drained the fluid and it is a "nice" shade of dark gray.

My son (armed with his digital camera) and I are going in to do some "surgery".

My question is: Do I need to pull off all of the ancillary items (rear, governor etc.) to replace the B3 frictions?

Any thoughts and thanks,

The Tenor Man

P.S. I've attached a photo of the "patient".

david s poole · #2 06-03-2009, 09:42 AM

no you don't all that can be done through the front after you remove the front pump,but if you have gray fluid it sounds as though aluminum metal parts have been grinding up into powder.there may be more here than the reverse clutches.

the tenor man · #3 06-03-2009, 12:16 PM

Mr. Poole,

I found no metal of any type...nothing shiny like aluminum particles...just the gray powdery liquid...

I drained all of the old fluid out of the pan and torque converter, changed the filter, refilled the unit. Still no positive reverse, but the fluid had very little gray left.

I then went on a long test drive around the neighborhood...forward is fine with no hesitation or flare...all forward gears seem to be fine.

I am a bit leery about just replacing the reverse frictions. I could hate myself in the morning.

I'll keep you posted and thanks,

The Tenor Man

david s poole · #4 06-03-2009, 12:51 PM

powdered aluminum looks gray not shiny.i think you may have some issues with the reverse piston grinding on the front clutch drum but when you get the front pump out we will know more.

the tenor man · #5 06-08-2009, 12:06 PM

Hello all,

We're still working to remove the transmission from the 1989 190E 2.6...hopefully within a week or so.

I found that Bobby Rahal of Pittsburgh can get the B3 piston for $110.00...I don't think that's too bad...and the four frictions at about $12.00 each. Hopefully, I won't need any of the "steels".

I'm afraid of a "bone yard" unit because it may have the same "no reverse" problems and most are really old and have high mileage.

We'll take photos of the disassembly...and post them here.

I welcome any suggestions and many thanks for all of the help.

The Tenor Man

ajme · #6 06-09-2009, 12:38 AM

Hello Tenor Man;

For what it is worth, here is my experience on a 1989 190e 2.6. Reverse slowly failed, until it would no longer back up even a gentle slope. The fluid was grey, but there were no chunks in it.

The pistons were all fine, B1 and B2. The bands still had the printing on them: zero wear. The steel clutches were fine. The governor was fine.

The problem was a cage that holds a couple of dozen small coil springs, which keep the reverse clutches apart. The cage had blown up, releasing the spring pressure. The reverse clutches had, therefore, been at least partly engaged while going forward. This obviously resulted in wear of the reverse clutches. Fortunately, I took ours apart just as the friction surfaces were about to disappear, so there was no damage to the steel plates.

There was also a large circlip that had broken, but it was not generating any symptoms.

I got a kit with all the o-rings, gaskets and fibre plates, off the internet, for cheap. Most of the parts had Mercedes logos on them. Replacements for the rest of the broken parts. and a set of the little coil springs, came from the dealer, at reasonable prices.

Now it shifts perfectly, and no longer leaks.

I would advise holding off on buying parts (except the seal, gasket and fibre plate kit, which is essential) until you see inside.

By the way, the kit does not include the two large o-rings (size dash-153: 3 1/2 inches inside diameter by 3/32 inches thick) which are inside two of the asemblies. I used inch dimension rather than searching for metric. They were close enough that they might have been designed fro inch o-rings. The procedure for replacing them is set out in a pamphlet on the Transtec/Corteco website, if you are interested in doing the complete job ("K1 and K2 Support O-Ring Replacement", in a pamplet on Mercedes 722.3 and 722.4).

Good luck!

Andrew
1989 190e2.6 and a couple of old Jaguars.

pawoSD · #7 07-09-2009, 09:59 AM

And that is why I am taking mine to the rebuilder! White magic light inside!

ajme · #8 07-09-2009, 10:11 PM

Hi Tenor Man;

That is the same failure mode that I had, except that your friction plates are not as far gone as mine were, and I also had a broken huge circlip.

My K1 drum also looked just like that. I figured that there was no actual material gone, and I don't think that there should be a lot of differential rotation under pressure requiring a smooth surface. The wear is caused by the broken parts contacting when they shouldn't. I just left mine. It seems to work fine, although I suppose it could be a time bomb.

The small seal comes in the gasket/seal kit. The only ones that don't are the two large ones hidden inside the K1 and K2 drum assemblies (the ones that you have to drill out rivets to get at). They are a bit tricky, but the Corteco pamplet tells you how:
http://www.transtec.com/tech_insert/94642.pdf at page 7. Mine were maybe still sealing, but they were hard like bakelite. I replaced the rivets with bolts as directed, and used lots of loctite putting them back together.

The springs and the broken spring holder are cheap from the dealer. I got a seal and gasket kit, complete with friction plates, on e-Bay. It was great. Most of the friction plates were genuine Mercedes. There is a kit for the 722.4 transmission on e-Bay now, which seems to include the friction plates (the picture is small), for $240 (which seems highish).

Andrew

the tenor man · #9 07-10-2009, 08:17 AM

My first thought was to get another K1 Drum...but i may try to polish the surface smooth again.

I'll need to check the shaft and see if the circlip is still on the shaft...it didn't fall out with the rest of the parts.

I'm lead to believe that something caused the spring cover to ride on the K1 housing. I'm not convinced that the spring cover is a "wear" item. I don't think that it should ride constantly on the K1 drum surface. In reverse, it probably does. But once the transmission is no longer in reverse, I'm assuming the springs are to back-off the B3 Piston and release the reverse clutches...but I could be wrong.

This has been a great learning experience for me...and many thanks to all for the valuable help..

The Tenor Man.

gsxr · #10 10-01-2009, 07:01 PM

Any update?

whunter · #11 10-04-2011, 06:02 PM

I received a couple of calls today asking if I know this worked out.

lsmalley · #12 08-26-2012, 07:54 PM

Its been about 3 years now.....wonder what happened with this.