Folks:

Took vehicle to a local shop to get the transmission fluid and filter changed. 2010 E550. They filled it up with Pentosin ATF 1. http://www.pentosin.net/specsheets/pentosin_atf1.pdf

Vehicle started lurching and hard shifting immediately on test drive.

For the 722.9 transmission, 236.14 is the current spec sheet and Pentosin ATF 1 is not correct. Looks like it is spec'd for "vintage" Benzes.

Whereas, Pentosin ATF 1 LV claims to be spec'd for 236.14. http://www.pentosin.net/specsheets/Pentosin_ATF1LV.pdf

My question is, could a few miles (less than 5) of driving this vehicle on this incorrect fluid, cause permanent damage?

Am I correct that the procedure now to get it all out is for them to drain the entire transmission and torque converter twice and refill twice?

Thanks for all responses! Concerned about this transmission.

Make sure what happened is documented in writing and you have proof of what was installed and when it was done by the shop. You have no worries if you keep everything in writing as to what happened and what it caused your car to do. Put it in writing to the Shop owner. The shop's insurance company will need to be notified and you should get a new or at least a Mercedes transmission supplied by and installed by a Mercedes dealer. You cannot take a chance on damage that will not show up until 5,000 miles from now. The shop is totally liable for getting you a new transmission. If they don't want to contact their insurance company then contact your automobile insurance company and maybe a lawyer. But very very important to get everything in writing and get shop manager or owner to sign off one receiving information and to what happened. This can be costly to you if you play nice.

I wouldn't let this shop touch my car again. I would take it to the dealer and have them diagnose and see if just replacing the fluid as you mention is sufficient. Better to have someone independent of these guys handle it. The local shop should cover the cost and even refund you the original cost. Don't sign anything with the local shop.

That's nasty. Hope it works out OK for you as you are looking at upwards of $7500 for a replacement transmission they tell me ($10k up here)
As suggested document, communicate and sign no releases or any other document.
Maybe get it put on a flatbed and to the dealer. Maybe they can open it up, flush it and replace the filter and perhaps save it.

Thanks for the responses! I'm torn on whether to at least let them flush it twice and refill and see if it returns to normal operation. It was driven only a few miles on the fluid. It appears that their supplier sent them the wrong fluid.

I suppose my question is, how likely is it that the brief introduction of the wrong fluid caused physical harm to the transmission? Both fluids are similar full synthetics but with different characteristics. Just curious on a technical basis how the tranny reacts to a fluid with different viscosity etc.

You might want to call or stop by another reputable tranny shop and see what they think of that question. I would at least get some advice from an experienced mechanic that is independent from these guys. And even then, are these mechanics really going to know if this causes early failure thousands of miles from now? Ask yourself this question though - if it works fine after the flush with the correct fluid, how long will you be looking over your shoulder and cringing over any odd noise or vibration? Just trying to watch your back.

+1...don't take any chances!

Thanks. I will call or stop by the dealer tomorrow and ask their tech what should be done about this. I'm sure this is not the first time that they have seen this happen with an indy-shop.

Do you have 7500.00 to gamble that a flush will fix it? Because if that is done and it drives fine for 30 days then fails, then its more than likely on you to pay for repairs and not the shop. The suggestion of taking it to a Mercedes dealer is a good one but it must be at the expense of the shop at fault. Get everything in writing. Get the shop to put you in touch with their insurance company for the liability so the paper trail can start. If you cut corners and do things verbally you can get hit with the cost of a transmission.

No, sir I certainly don't. Especially not due to a bozo mistake by a so called shop that I paid to do it correctly. I will contact the dealer. This is such a headache.

What he said!

I like the excuse "the supplier sent the wrong fluid" vs, "we are dumb asses and used the wrong fluid"

Ditto. Though I would be interested to see what the dealer suggested.

You're in for a battle. This shop is going to fight you tooth and nail

Good luck

The wrong fluid probably lubricates the gear wheels just fine and no premature wear happens during a short time you have the wrong liquid in the tranny but this is not the damage that you need to worry about.


Different types of rubber materials absorb different chemical and if you fill the tranny with a fluid that the rubbers seals inside the box absorb you are in trouble. The seals will swell and cause moving pistons etc. to get sticky making bad shifting or some gears may not work at all. It is the most important thing to drain the wrong fluid out ASAP and then flush the tranny with the correct fluid and doing this twice will not hurt either.


If after the flush the tranny works ok with the correct fluid you probably have not experienced damage at all.

Arrie "If after the flush the tranny works ok with the correct fluid you probably have not experienced damage at all."


That word "probably" would make me feel very uneasy about reliability.

I would think the dealer could add weight to any claim you have with the shop. I sort of doubt that 5 miles will destroy the transmission, but there may be that issue with fluid chemistry vs the rubber bits. I would not take it back to the shop. What I also wonder about is if that shop may have nudged a connector out of place to contribute to the sudden weird shifts. I would also ask the dealer to initially report on the fill level of the fluid that the shop put in, very low or very high fluid can also cause the bad shifts. Either way, suggest the dealer to be your next stop.

Not trying to pour salt into a wound but I'm curious. Assuming "local shop" means it was not an MB dealer/service, what was the purpose of doing that? Was it saving some $$ and if so, what would have been the savings, assuming everything had gone right? I never take my cars to independent shops because of horror stories I've heard over the years.

Well, one exception, I did bring my C300 to a local tire shop for new tires. They generally do a good job with replacement. When they offered to do a free check and alignment if necessary, I went for it. That was a mistake because they totally messed it up. I had MB adjust it and everything was good again. It would have been cheaper overall if I had gone to the MB dealer in the first place and I know they will stand behind what they do.

All that said, I hope the problem gets resolved soon and to your satisfaction.

That's pretty scary to hear. Good luck to OP.

Hope the shop comes through and fix your tranny properly for you OP.

BTW, what was the charge for the transmission service if you don't mind telling?

ohh man what a headache!!! good luck!!

I would demand a new transmission, period. You will never feel confident driving long distances with this car. I wish you well with this disaster and the statement about receiving the wrong fluid is a complete cop out to redirect the blame.