Transmission Overheating Help Please.

[fester]

Originally Posted by hotqld

Thanks Guys for your help,
I drained the trannie oil and have about 3.5 ltrs. Same as what you mentioned for the WG. The previous owner changed the trannie oil himself.

When I refer to my service manual for the 3 ltr CRD it says 7.1 litres for a service and 9 ltrs for a rebuild. My oil suppliers lititure said I needed 9 ltrs as well, So appears it has been running on 40% of what it should have been.

We do have a dipstick thingie but they try to hide it.
see attached apparently they wont sell you a dip stick , but I used a stiff wire about a meter long and apperently they are on ebay.

Yesterday the jeep would not drive when on a really steep hill but when returned to flat it went into drive only 1st.

I reckon it is in limb mode, my code reader would not get it out and disconnecting the battery for 15 minutes hasnt worked either.
any other ideas?

Maybe when I fill the trannie tommorrow it might? , I had to wait for a trannie filter.

Comments / help very welcome

Yes the dipdtick tube is still there, yoou break the little locking tab and then you can pull the cover off. I think you cna get the tab off without stuffing it completely and reuse it. You can use a wire which is pretty much all the ebay ones are except they have the correct graduation on them. There is a measurement for cold and for hot and you have to read it at the correct temperature. Most guys on here and elsewhere I've read generally get about 3.5 litres out from a general service. Drover has detailed his a couple of times on here. I know the full capacity is 9 litres but not sure where the service manual comes upo with the 7.1. I'm pretty usre ont eh Merc forums they do not come up with that much either. The early Merc boxes had a drain plug in the torque convertor the later ones do not. This is why you get so little out. Some people drain it a couple of times to get more new oil in but bear in mind you are only ever getting a percentage out and some of this is mixed with new of course so you are just gradually watering down so it's debated if it's worth it unless the oil is particularly contaminated. There are write ups around where you disconnect the outlet cooler line and pump out a litre or so, top up and redo a few times. Up to you if worth the effort.

Do not overfill the box or you will have dramas from that as well. Your code reader will only clear ECU codes not TCM codes. The TCM throws a code and then triggers a code in the ECU but clearing the ECU does not back feed to clear the TCM. Bear in mind you could have an electrical problem instead so make sure your battery is good, and your earths are good and the wiring plugs to the tranny as good.

Keep an eye on the electrical plug to the tranny which is on the drivers side. It can be the source of a tranny leak and if bad enough the oil wicks up the wiring into the TCM.

If fresh oil does not clear the issue I really think you need the box read at the dealer before you problem solve further.

[fester]

http://www.scribd.com/doc/37436253/722-6#outer_page_13

That link has service bulletin info on the Merc box and the page 13 shows the dipstick measurements, it also explains how to change and check the oil. The only thing I don't know about the dipstick tool in relation to the measurements is how far it goes into the dipstick tube. The factory tool no doubt has a head and therefore bottoms out on the collar on the head. The aftermarket tools are just a wire and therefore have to bottom out on the tranny pan. I'm noit sure if the factory tool does that. The previous owner of mine had both a petrol and diesel and swears the petrol dipstick is the same length as he tested it the first time he had the dealer do the oil. I've just had the pan off and the petrol dipstick stops about 30mm from the bottom of the pan. I need to clarify that bit with a Merc forum before I make my tester. I have access to stainless balustrading wire at work whihc is 1/8" and therefore perfect for a dipstick tool but I need to clarify the length correctly.

[piper]

i found that oil temp and oil depth did not seem to match so i put in 60mm from the pan bottom, with motor running and in park
i also flushed the torque converter from the driver side cooler line by undoing the banjo fitting, starting and stopping the motor by releasing and adding a litre at a time, its a good idea to pull the filter apart to see whats inside, mine had
some metal,the banjo fittings can leek as well they have a o ring inside
i used fuchs aft 4134, 12lt at $20lt

[fester]

Piper is that the line off the box. How does that pipe lock in to the banjo fitting if it has that oring inside. One of mine could be leaking a little but I suspected the aluminum washers either side of the banjo fitting itself. I expected the pipe was welded or fused to the banjo. So to seal it requires the integrity of 2 washers and an oring.

[piper]

yes Fester, they are the lines off the box, actually both my banjo fittings were weeping, they are 'o' ringed and crimped onto the tubing and you can rotate them. My 'o' rings were oval, so were loosing their seal, i made two new banjo fittings, cut the tube and joined with a pce of transmission hose and hose clamps.
You can buy the banjo fittings but i didn't like the restricted hole size

[fester]

Is there any reason for them to rotate given once in place they don't go anywhere it surely can't be for engine movement. No point getting a new banjo or oring given I don't have the tool to recrimp. Think I will pull that one off, remove the oring and weld it up. Best to do now before I put the fresh oil in.

[piper]

was going to silver solder but i was only going to burn the plating off then it would rust, so i decided to make them, you have to put the barb on a angle out otherwise the hose is too tight against the case,

there is a graph in the manual for oil height and temp so no need to guess
i put 60mm may be overfill but works

if the oil can go in a GM or a Ford its not for MB