My SDL slipping in reverse... - PeachParts Mercedes-Benz Forum

MercFan · #1 07-26-2010, 11:42 PM

Well, it happened once before and I dismissed it... today it happened again. The car was parked for about 2 weeks while we were vacationing in California. Got in today to drive out to the airport and when I shifted into "R" and stepped on the accelerator it felt like the transmission was slipping. The engine started right up and it purred normally but the reverse gear did not operate as 'normal' - it was definitely sluggish. I ran it to the airport (25 miles) with no issues and tried it again in the parkinglot there - no issues then.

I have to also say that the transmission has a slow leak from the gasket (i think), but when I checked the fluid level before vacation it was right in the proper range.... the fluid and filter change is on the list very soon - got to read up on the proper procedure.

Is there anything to suspect in this case - after some searching it looks like possible early warning signs for B2 piston problem? What else could it be?

James

TX76513 · #2 07-27-2010, 08:39 AM

Hopefully a Transmission service will bring it around for you. On the older transmission the B3 Piston finally starts not to engage the friction discs. Which isn't the end of the world - but start with a service.

MercFan · #3 07-29-2010, 03:44 PM

I've searched the forum for transmission fluid recommendations - found references to Mobil 1 Full Synthetic ATF - is this a good way to go?

Also, is there a DYI on atf change including the TC? I know know why but I'm nervous about changing the fluid in the trans... not clear about the process of filling the TC afterwards, starting, stopping, re-filling. Where can I get the concise steps for doing this right?

THanks,
James

TX76513 · #4 07-29-2010, 03:50 PM

Well oil threads can get way out of hand here. I use AF3 grade - others use synthetics, AMSOIL, etc, etc. I have my personal thoughts about switching to synthetics in older motors/transmissions (that have been using dino) but I will reserve them.

At the top of your screen there is a tab "Resources" click that and select DIY Articles. You should find a wealth of information in there.

When you switch from P to R how much of a delay is there before it engages?

MercFan · #5 07-29-2010, 04:12 PM

Quote:

Originally Posted by TX76513

When you switch from P to R how much of a delay is there before it engages?

This morning: none - worked perfectly. It appears that this issue happens after the car has been sitting for a long time - i.e. week or 2 weeks. WHEN it happens, there is no 'delay' before it engages... it simply acts like it's sitting in N even though I've shifted. Revving up the engine either doensn't engage the transmision fully OR it feels like it's starting to 'grab' a little but it's mostly slipping as it delivers very little power to the rear wheels - the car barely moves back...

On the trans fluid - Dextron ATF type III, is that what you use?

Finally, what is the transmission number that I have in this '87 SDL!??

TX76513 · #6 07-29-2010, 04:50 PM

Transmission is a 722.xx
Dextron is Fine

When you going to post a pic and show us what you have?

MercFan · #7 07-29-2010, 05:17 PM

Quote:

Originally Posted by TX76513

When you going to post a pic and show us what you have?

Hehe - you're right, I guess I need to do that very soon...

MercFan · #8 07-29-2010, 08:58 PM

I went down to AAP store earlier tonight and looked at various ATFs - here's the summary:

1) Valvoline MaxLife DEX/MERC (DEXTRON-II; -III -VI) - $5.29/quart

2) Mobil 1 Full Synth ATF - $8.99/q

3) Castrol Dextron VI - $6.99
Castrol ATF+4 - $5.99
Castrol MERCON V - $5.09
Castrol Dex/MERC - $4.19

Are any of these better for the SDL than others? Plz no oil-thread like behavoiur...

pawoSD · #9 07-29-2010, 10:40 PM

When my reverse started slipping on my 300SD right around this time last year, two weeks later I was installing a good used trans.

I found clumps of clutch material and a piece of the brake band spring in the pan. Reverse was nearly gone. I put in an '85 trans with 160k on it (mine had 281k when it died) and it has been great! In fact, I rolled 300k with it two days ago!

MercFan · #10 07-30-2010, 12:08 AM

Let me ask this question differently: what classification should I be looking for on the back of the label: meeting or exceeding Dextron III, or VI?!

Admin folks - it would be super cool if we had a section on the recommended fluid types.

MercFan · #11 07-30-2010, 11:38 AM

If noone knows - where do I look that up?

Answering my own question here.... After exchanging PMs with B.C. I'm going with Valvoline MaxLife Dex/Merc - for $5.95/quart - I've determined that my transmission is 722.3 so 6.2 or 7 quarts is needed to refill.

pawoSD · #12 07-31-2010, 12:39 AM

I've been running the Valvoline Dexron VI Full synthetic in all 6 of them in my family for years with excellent results, especially in the cold.