Bc did that with the 300se that I sold him. I don't remember exactly but I got the impression that the power is a bit too low on the m103 to handle the 2.88? Diff I think he installed. Just required a different driving style and a bit of manual downshifting.

__________________
Eugene

10 E63 AMG
93 300te 4matic
07 BMW X3
14 Ford F-150 Fx2

Could one not adjust the kickdown functions on the tranny to compensate?

Also curious to know what rpm this delivers at freeway speeds, and if there is an online list of ratios used on the various models.

Yeah, there is a good thread on here about switching out the diff. Do a search on 300SE diff and it should pop up. The bottom line was that 4th gear was just too weak to handle even a slight incline at highway speed, and with a big jump down to 3rd, it made for unsatisfactory results. Modern cars downshift all the time on the highway, but usually it's just the torque converter unlocking, or if it actually downshifts, the gear ratio spacing to that lower gear is a lot less than the Benz 722.3 from 4th to 3rd, so not as noticeable. The tranny must be modified to start in 1st, there are a couple of ways to do that, but it's somewhat involved, and the 1-2 shift can be harsh. At 60 mph the stock 3.45 diff turns right at 3000 RPM, so the 2.88 would turn about 2500. Seems fine, but apparently not in the real world of low engine torque, heavy car, and hills and winds.

DG

2.47 in a 300se

http://www.peachparts.com/shopforum/tech-help/304913-2-47-300se.html

It's a good factual read.

__________________
Eugene

10 E63 AMG
93 300te 4matic
07 BMW X3
14 Ford F-150 Fx2

Old thread, but I will chime in.

I purchased a '88 300SEL in 2008. I specifically wanted a 300SEL and got a great deal on this one. Purchased with around 153K miles, then the odometer broke about 1500 miles later and I never did get it repaired. I estimate around 175K on it now. I drove the car for a couple of years, then gave it to my mother in 2010.

The car has been very reliable. The main issue has been the A/C and no one has been able to figure it out. The A/C will blow ice cold for a long time, but you stop somewhere and turn the car back on, the A/C blows out hot air and will not blow cold air again until the next day. One shop said it was a bad control panel, had that replaced, still a problem so we gave up on it. Mom does not drive much, so not too big of a deal. Other than that, one time it would not start, turned out being a bad coil. Few minor things with age, a couple of power steering hoses leaking, the front oil cover leaks some oil and it has for a long time, but we keep a close check on the oil and it does not lose much at all between changes and recently the transmission will lose some fluid if parked at a certain angle. It looks like the pan is leaking, but it is due for a fluid change, so getting to that soon. Also, trunk leaks. Our car has never been in salt and is rust free, but the trunk seals on these tend to crack and rust around the seal on the trunk - we are dealing with that soon as well.

You also have to make sure you clean out under the fuse box under the hood ever season to get out old leaves as they tend to collect under there and there are hot relays under there which could catch fire. Not a good design, but one Mercedes overlooked I suppose.

I will say the car is no power house, but it was always good enough for me, as my Mercedes before that was a '84 190D. My Mercedes now is a '93 W140 with a V8, a much more powerful car, but more complex and has not been as trouble free despite it being a well maintained 1-owner car.

I always preferred the 6-cylinder W126, because it also seems to have less transmission problems, as well as few problems with the timing chain guides/rails. I have never heard of this problem on the 6-cylinder, but have several times seen a V8 W126 where the chain guide/rails/tensioner can break if they have not been changed and become brittle and destroy the engine. Does not seem to be the case on the I6 versions - or not as common anyway.