'87 300 SDL - No Reverse, May Sell - Page 2 - PeachParts Mercedes-Benz Forum

loepke72 · #16 01-03-2011, 01:06 PM

The 722.3/.4 transmissions do not have a "reverse band" despite the B3 designation; it's a multiple disc holding clutch. Not sure what causes the friction disc failure, but that normally results in delayed reverse engagement. Another failure is a cracked reverse piston which causes no reverse at all.

I wouldn't do a patch job on one of these units (or any other transmission for that matter) due to age and mileage for a paying customer as the risk of having something else fail shortly thereafter is too great with the customer screaming bloody murder. If the unit is late model and low mileage, well OK, but not on something 25 years old. I've seen too many hardened O-rings in these transmissions to not do a full overhaul on each one.

Gregory · #17 01-03-2011, 01:46 PM

On the 1987 300 SDL, is "722.3/.4 transmission" the correct OEM tranny?

loepke72 · #18 01-03-2011, 02:31 PM

Your car should be a 722.3 (722.325 if I remember correctly but check yours to be sure) transmission. 722.4 was a smaller version of the 722.3 used in the W201 (190 series) cars but nearly identical to the 722.3 but with smaller internal parts and case. Your transmission will be a first gear start (starts in first gear), unlike the gas engine 420/560 cars which start in second gear, allegedly to reduce the likelihood of wheel spin on acceleration from a stop (but could downshift to first with the kickdown switch under the accelerator pedal). Only differences in the two versions of the 722.3 is the valve body and the bellhousing depending on which engine it was installed with.

HuskyMan · #19 01-04-2011, 09:50 AM

If it were me, I'd put a new radiator in. If the transmission cooler/radiator barrier fails in an older radiator, the car will need another transmission. Either that or find a shop that has a hot flusher to flush the metal debris out of the transmission cooler.

Gregory · #20 01-04-2011, 08:11 PM

I had another shop take a look at it. They took off the pan and found a lot of metal sludge. The tranny was serviced just 2 months ago so all that sludge appeared since then.

These guys suggested installing an aftermarket trans-cooler. They said its nearly impossible to clean all the gunk out of the lines and radiator transmission cooler.

He said the aftermarket kit cost about $90 and was the best insurance against the replacement tranny being damaged by gunk in the system.

HuskyMan · #21 01-04-2011, 09:37 PM

Quote:

Originally Posted by Gregory

I had another shop take a look at it. They took off the pan and found a lot of metal sludge. The tranny was serviced just 2 months ago so all that sludge appeared since then.

These guys suggested installing an aftermarket trans-cooler. They said its nearly impossible to clean all the gunk out of the lines and radiator transmission cooler.

He said the aftermarket kit cost about $90 and was the best insurance against the replacement tranny being damaged by gunk in the system.

go to this link and watch the demo. You can phone the company to find a trans shop that has a hot flusher. as stated earlier, either get it to a trans shot that has a hot flusher system or have the shop install a new radiator.

http://www.hotflusher.com