tw2

I am going to do a transmission flush. No idea if or when it has been done before but I am fairly sure the red lock pin is gone and replaced with a black one so hopefully happened sometime in the last 136,000km.

I will get the gasket, lock pin, drain bolt/washer, filter and electrical plug/bush (with O ring) from mercedes. They are quite reasonably priced. Their 236.14 transmission fluid is not. Its about $52 per liter but there aren't many options here. I can't find mobil or shell 134. Also the trans dipstick from ebay (mercedes refused to sell it to me) and an infra-red temperature reader.

The local parts store has some fully synthetic "Penrite" tranismission oil which meets MB 236.10 and 236.12 specs at $12 per liter. Penrite doesn't come up on any searches and I have no experience with it. Can I assume that it must be fine since it meets the specs? I presume they need rigorous testing to put that on there?

Any other preventative maintenance around the transmission I should consider doing at the same time as the flush?

Kustom1911

When I do a trans flush, I always have a new trans cooler line O-ring (MB # 028-977-62-48) on hand, but I see that you might have a aux. or isolated
trans cooler, if I read your post correct.

Back in the fall of 2012 I noticed that the MB spec 236.14 was updated, and Valvoline Synpower ATF 134 was added if that helps you any.

You might want to check if the "Penrite" is on an MB updated spec list.

Best Regards

Kustom1911

I checked the current MB 236.14 spec approved list dated 10/2/14, and Penrite is not on it. So I would think twice about using it.

When I do a flush, I use at least 12.5 qts. but most of the time I use nearly 14 qts. so if you have that much of the wrong fluid in the trans, it will be a big and costly problem.

Just my .02, Best Regards.

tw2

Thanks for the advice. I have a copy of the 236.14 recommended fluids. I haven't been able to find a copy of the old 236.10 fluids list. Penrite are an Australian company which will be why they aren't in the US I would guess. The bottle says "Industry standards" and below that there is about 20 standards including 236.10 but I don't know if that means they actually underwent official testing. I might stay clear of it.

I went to my local indy to see what fluid they use (fuch titan) but they were incredibly rude, condescending and unwilling to have a calm logical conversation so walked out, I was considering having them do the flush but they won't be getting any more of my business now. They claim it is impossible to do the flush without star to get the fluid level correct, to get the maximum amount of fluid out during the flush and the transmission adaptations. They also tried to tell me you need to plug in before the flush to get the current adaptations from the car, maybe they are confused with the 722.9 7-speed transmission? They also didn't recognize WIS as a credible source. I think I trust MB WIS and Glyn more than these people.

Anyway I think I will do a pan drop and fill with MB fluid, not bother with a full flush and do it every 30,000km. Has to be much better than doing nothing at all and MB quoted me $850 last time I asked.

tw2

I found this in the thread https://mbworld.org/forums/clk-class...2-6-atf-6.html this answers my question. They do not use the standard phrasing.

Kustom1911

I agree that WIS and Glyn are your best source for info.

If you want the latest 236.10 approved list search "Mercedes BeVo 236.10" and the official page comes up, and you can see other approved fluid specs there also.

A few years ago I contacted my local Shell dist. and he told me he would be happy to sell me a 55 gal. drum of ATF 134, as it was the only way to get it. I knew that was false, so I called another and got the same response, I called a third one and they could get 12 qt. cases in 2 business days. Just depends on the person you happen to contact, so don't give up too soon.

I do not know the oil distribution system in your country but I am sure there is a cheaper alternative for you. I agree that a pan drop is the next best alternative. Best of luck to you in your search.

tw2

Well I got all the parts and did the fluid change yesterday. I got 5L of MB oil from the dealer, very expensive but I am happy with my final decision. I also got the filter, new drain bolt and washer, new locking pin and electrohydraulic bush (plug socket with O-rings).

This is a fairly simple procedure. The electhydraulic bush required a bit of work. Make sure the pins are definitely lined up well before pushing it home. Otherwise if you break one you need a new conductor plate ($700-1000) and needs STAR from what I understand. It requires more force than I could muster with my fingers only from under the car. I used a 32mm socket over the brown plastic end and gently levered it in with a short bar, worked perfectly.

These are the threads I found very helpful for anyone looking at doing this:
http://www.benzworld.org/forums/w210...tor-plate.html
https://mbworld.org/forums/c32-amg-c...ion-flush.html
https://mbworld.org/forums/c-class-w...sues-help.html
https://mbworld.org/forums/c-class-w...n-related.html
https://mbworld.org/forums/c32-amg-c...ush-today.html
https://mbworld.org/forums/clk-class...722-6-atf.html

tw2

The problem I have now is getting the fluid level correct. I put in 3.4L as this seemed to be the most common volume needed. I measured 3.1L removed but there was a huge puddle despite my best efforts. I drove 20 mins. Checked level with the dipstick and engine running. It was half way between the 25 and 80 degree markers and the pan showed 70 degrees with the infrared temperature gun. I added 350mL in increments to get just above the lower 80 degree line.

Then today drove to work and took the long way home but still only about 10-15mins driving and it is back to half way between 25 and 80 again. Its raining and dark but I think it said 50 degrees on the pan. There are no leaks I can see on the ground in the garage. Add more fluid? longer drive? do you really have to thrash it to get to 80 degrees (or close to since I am not reading the direct fluid temp)?

Glyn M Ruck

Sorry. I've been travelling. I'm pleased to see you used the correct fluid. I'm really tired of arguing these issues.

Kustom1911

It is not uncommon to have to add a little extra after driving for 20 miles after a change, filling the voids in the trans.

Yes trying to get a 722.6 trans to 80 degrees centigrade short of being on a racetrack is hard unless the ambient temp is hot. Each of the 4 times I have changed & flushed my wife's CLK500 trans it has been cool or very cold, and I can never get it up to the 80 degrees to check properly. I had a friend that gave me an old chart out of a 722.6 training manual showing fluid levels. I have used this all 4 times and it has worked for me like a charm. Every time I checked the trans after the weather was hot and I could get the trans up to 80 degrees, the levels were 1/2 between the min.& max, perfect.

Here is my procedure:
I warm up the car on the hoist, putting the trans in each gear several times, let it get to 25 degrees C, trans to 1/2 between min. & max.
Take out and drive for approx. 3-5 miles, check fluid level & temp to make sure enough fluid in trans before trying to heat up trans.
Drive for 20 to 30 miles, check fluid level & temp, refer to chart. To be more accurate i measure from the 80 degree Max. line down, due to different dipstick manufacturers.

Warning: This chart is only for correct trans dipstick with the black plastic diamond, which restricts the end from hitting the trans oil pan.

@120 degrees F, I want to 27mm down from 80degrees C Max. line.
@140 degrees F, I want to 18mm down from 80degrees C Max. line.
@160 degrees F, I want to 12mm down from 80degrees C Max. line.

Hope this helps you, Best Regards

Rudeney

One way to get it to heat up quickly is to put it in gear, hold the brake, and increase idle speed.

tw2

Thanks heaps for that, extremely helpful. I got 18mm down from the maximum of the 80 degree marks at 62-65C degrees which is 143-149F. This would mean I have it about right and considering it is the max line it shouldn't be overfull?

My dipstick has 75mm of graduations, 10mm, 10, 35, 10, 10 as per the OEM one. It has a pointed end kind of like a diamond...

tw2

What rpm would you suggest? Does this stress the torque converter?

Glyn M Ruck

The torque converter is what really heats the fluid. Doing this judiciously will not stress the converter as much as a WOT launch from standing.

tw2

Makes perfect sense, thank you very much Glyn and Rudeney, I didn't find any mention of doing this procedure to get to temperature anywhere. Anyway I launch the car from standing somewhat frequently for better or (much) worse but I try and maintain it well to make up for it.

For anyone else doing this, from cold I drove around for about 5km just to warm it up as much as easy driving can (54 degrees C in this case). Then I held it at 1200rpm in drive, foot on the brake for 70 seconds - 65 degrees, then another 90 seconds - 80.2 degrees and the fluid level was 3-4mm above the lower 80 degree line- perfect. This whole process will be simple next time I come to do it. I can finally put the new locking pin in when the car cools down enough.

Some pointers I learnt from doing this:
- if you remove the intake (CLK55 at least) a small funnel will fit perfectly on the filler so an annoying flexible tube or pump is not required but pour SLOWLY (I didn't spill a drop on the filling).
- if you drain the fluid by dropping the pan (and don't measure all of it, if you're like me and make a mess) expect 3.4L as a rough guide to get you almost back to the correct amount before you fine tune the last little bit. Certainly it will be safe to drive.
- my filler tube did not have a lock pin, only the cap for the last 12,000+ km it would seem (thanks last owner) so if anyone is concerned about driving around for a few days getting the fluid level perfect without the locking pin you don't need to worry about it.
- this is a fairly simple procedure once you read up about it and know what to do. If you can change spark plugs and engine oil you can do this. I did it with jack stands and crawling underneath the car. Just take your time and be very clean so as to avoid contamination in the pan and follow the torque values to the letter. 20Nm pan drain bolt, 8Nm for the six pan bolts, 4Nm + 90 degrees for the electrohydraulic bush with the small bolt- I didn't find this one out until later, I just tightened it as hard as I could only using the socket and my fingers to turn the socket extension and then 90 degrees with the wrench.

maxoujm

How to reach 80 ° and check with ??????

Yidney

The posts above tell you how to reach the right temp. Basically just let it run in gear. Since I'm sure you do not have the diagnostic system to check it directly, buy an infrared thermometer - looks like a little gum that shoots a laser beam - and point it at the tranny pan. That's close enough. At least on my car the temp to check fluid was 113 F. Warms up pretty slowly.

maxoujm

I own this model




when lazer is on the housing does not indicate 80 °


temprerature is 73 °

Yidney

What? Are you saying that your tranny is always at 73 dgrees no matter what?

maxoujm

the temperature is between 67 ° and 75 ° and not more!!!!!!


what should I do ???

tw2

Read the posts above. Foot on the brake, car in drive, gently raise the rpm to 1200, that will get you to 80c in a minute max. The torque converter will heat the fluid very efficiently.

maxoujm

Ok
no risk to the box ???? Skating !!
I will try tomorrow
thank you a lot

tw2

No, it is much easier on the transmission than launching it at the intersection which I do frequently. If you drive around to get it up to about 65-70 degrees it will take very little time to get to 80 using this approach. Be aware it cools very quickly once you stop.

maxoujm

No, it is much easier on the transmission than launching it at the intersection which I do frequently


I do not understand !!"I amFrance"use(Google Translate)

tw2

C'est ne mauvais pas pour le transmission. Vous avez le CLK500? Quelle annee?