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Well, you have to keep in mind, your in a luxury car of its era (20ish yrs old or not) and the sounds you'd normally hear in a lesser vehicle, you won't hear with this one. But this trans is, as stated previously by Addicted, is generally quite stout. That is why the code is important.
If this was a ZF5, in a standard XJ8, we'd have a real good idea what that problem was.
would be a great time to ask the benzworld guys.
ask the tech to grab some pics of the fluid and bottom of pan
I don’t have an owners manual for the SV8. I believe all the X308’s had roughly the same owners manual. I have one for my 98’ XJR and the wife’s 00’ XJ8 and they look alike.
I had the same incorrect gear ratio code in my 03’ SV8 when I got it back in June of this year with 115K miles on it. My transmission electrical connector was wet with oil. I took the pan off, replaced the electrical connector, replaced the filter and pan gasket. I then cleared all the codes in all the modules followed by a hard reset. Driving it regularly and having a good battery has yielded no further issues with the car. If I were you, I’d insist on having this repair performed prior to having them shotgun another transmission in its place of the current one. I’m not saying it’s impossible that the transmission is bad, but the likelihood that it is, is far and few between. I believe the mileage and year of your car reflects that it’s been sitting a lot and it’s more likely that the battery doesn’t provide enough amperage and voltage during engine cranking to satisfy all the modules in the car is more likely the cause. Throw out the idea that the engine cranks up and runs just fine, it’s more complicated than that. *IF* by some chance the transmission comes out, make sure they replace the rear main seal AND the cap seal 2” above it. It needs a 17mm Allen socket to remove it. It’s not just mileage, it’s age also.
This is transmission electrical connector you will want to replace.
Last edited by Addicted2boost; Dec 22, 2020 at 07:51 PM.
I'll give him a call and ask for the specific code it pulled. It was so weird though. It was just so sudden. No warning signs or anything...
The only code with description "Incorrect gear ratio" is P0730. It describes the reasons for it as either "Transmission oil level low" or "Transmission mechanical / hydraulic failure".
Before thinking of replacing the transmission, do the following:
1. Replace the ATF filter
2. Check for leaks at the round connector on the transmission
If a leak is found, replace this part (easily available, often sold together with the filter as a kit)
3. Fill transmission with correct ATF and to the correct level. The ATF is Mercedes p/n 001-989-21-03-10 ("Approval 236.10" also stated on the bottle). This transmission (Mercedes 722.6) is very sensitive to the ATF level so it must be done correctly. The Jaguar manual contains an important note that "any overfill MUST be removed".
If your mechanic didn't know where the dipstick tube was, better take the car to a Mercedes mechanic who has experience with this transmission or do the work yourself (with the help from this forum).
The noise is not a good sign ..... Knowing if the original dip tube lock was in place would indicate if it was played with in the past. The connector fault is often odd operation.
With the low miles and no leaks -- the fluid should be fine. Have not touched either of mine -- my old MB had the connector leak at 125k ..so it got a service -- the fluid was fine. The box is sensitive to being low on fluid that's why it;s always important to check to see if there are any signs of leaking.
The MB box was used in many cars -- it was about the only one at the time that could take the higher HP. That's why it's in the "R" ... and not the Non-SC cars. The cost of the fluid back then would often cause alternatives to be used with not so great results. It's a shame -- well intentioned servicing gone bad.
$1900 is almost too good of a price .... I would ask a few more questions
Ok, so I just got off the phone with the mechanic. It was P0730 code.
Now that the emotions kind of died down and I thought back on what happened during the drive. When the issue first started the transmission definitely felt like it was slipping. Like driving a manual and the clutch is out only halfway. It would only go to 2nd but it was slipping badly by the time it go to second. Then about 10 seconds of driving the gas pedal wouldn't do anything. Turn off the car and turn it back on, same thing until the has pedal wouldn't do anything in D and R...
The symptoms you describe could all be due to low ATF level and/or clogged filter. Low ATF/clogged filter usually also cause noises from the transmission as the air is sucked-in by the hydraulic pump. This causes drop in the fluid pressure and clutches slipping or jumping out of gear.
As the simplest and cheapest first step, I suggest you do what I described in post #23 above. If not done before, your ATF and filter are twice overdue for change. Although initially the ATF was considered to be good "for life", Mercedes, in Nov 2004, issued a Service Sheet AP00.20-U-1208IB (attached) calling for the “once at 39,000 mi” fluid/filter change for the 722.6 transmission. This appears to mean change only "once", at 39,000 miles (and not "every" 39,000 miles), but I would do the change every say 40,000 miles.
The symptoms you describe could all be due to low ATF level and/or clogged filter. Low ATF/clogged filter usually also cause noises from the transmission as the air is sucked-in by the hydraulic pump. This causes drop in the fluid pressure and clutches slipping or jumping out of gear.
As the simplest and cheapest first step, I suggest you do what I described in post #23 above. If not done before, your ATF and filter are twice overdue for change. Although initially the ATF was considered to be good "for life", Mercedes, in Nov 2004, issued a Service Sheet AP00.20-U-1208IB (attached) calling for the “once at 39,000 mi” fluid/filter change for the 722.6 transmission. This appears to mean change only "once", at 39,000 miles (and not "every" 39,000 miles), but I would do the change every say 40,000 miles.
Ok, it couldn't hurt. I'll see if I can get the mechanic to do that first. Thanks so much for a detailed explanation!
The service sheet in post #26 ... had a name and I do forget what MB called/ calls them. The 5 speed box variations was used in a lot of cars -- think this may have been for the C class that came in 01. It could have been the early lower powered E class models of 03. The service manuals still listed them as lifetime.
Anyway --- knowing if the black lock was still on the dip-tube would assure that your box had the correct fluid. If full it was not touched in its lifetime .... then you move on to looking at the fluid to determine if it has any water in it or any evidence of being overheated. Older fluid will have evidence of friction material -- this is normal.
The early MB boxes had firmware to adjust for miles -- in anticipation of the fluid property changing. The filters were designed for this as well-- it is the reason you see differences in the filters in the aftermarket.
If the dip tube lock was red -- this is evidence of it being replaced. You can't purchase the black locks -- this is how you tell if the transmission was opened. It's possible the fluid was changed.
Typically when a full transmission slips and fails ..... that's the end of it. Most decent shops work on the 5 speed ... how do you feel about the shop?
Also: If the connector is leaking ... you always want to use the OE MB part .... it's cheap.
So for an update. The transmission has been replaced with one from a similar mileage one. Mechanic said the transmission was done. I have no reason to doubt him as I trust him and he's never given me a reason to doubt him.
