If it slips between 1st and 2nd, that's pretty easy to fix. A shift modulator will take care of it. If it's slips between 2nd and 3rd, you might have someone check the B2 piston. 126 trannys of your vintage had a problem with that.

If it gives out, the MB rebuild mentioned above is a good alternative. My suggestion is only let a MB dealer or a shop that REALLY knows theese trannys.

Good luck

__________________
Mr. BILL

91 300E 120K
90 300SE 275K (sold)
92 BMW 525iM 120K
90 BMW 525iA 175K
85 300D 175K (sold)
84 300SD 245K (sold)