Will a 1989 420se diff work in my 1982 500se?

Hi I have a question about the diff lock on my 4x4 Terios 2009. My WhatsApp nr is 083 640 5317 and my e-mail address is [email protected]. I had the clutch replaced with a clutch kit and after that if I drive the car in the normal mode (without diff lock engaged) the car struggles to make sharp turns to the left and right and it almost feels as if the car is sticky. There is also a vibration or shudder on the car between 40 and 60 km an hour which is not felt if you exceed 80km per hour. There is also a high pitched humming noise audible when you slow down approaching a stop street. The steering wheel also feels tight, almost as if the power steering is not as effective as usual. HOWEVER, if I engage the diff lock all these symptoms disappear and the car runs very smoothly, it turns on a coin, no shudder at all, no humming noise, just a very smooth ride indeed. I almost get the idea that either the diff lock stays on/engaged in the normal mode and that it disengages when you press the diff lock button and the diff lock light comes on. In other words I almost get the idea that the diff lock system now works the other way around. What is your opinion, could something have gone wrong with the diff lock switch when the clutch was repaired?

80-90 oep diff oil unless it is a limited slip diff in which case you use special limited slip diff diff oil
don't know if it is limited slip diff diff
you can check by jacking up the rear end and having a friend turn a rear wheel
by holding one wheel the other wheel will be turning in the forward direct as that is what limited slip diffs do diff do ( both drive )
other than that call your local manufacturer service center and ask

It definitely has damaged the gears. May work for a while but rebuild or replacement is near.

I’m happy to help further over the phone at https://www.6ya.com/expert/david_66a56a0239b6ab32

mayb your diff lock switch was jam even there r free but it still giving signal to meter panel

pull the drain plug and check for metal bits on the magnet. The only items working when changing direction is the side gears in the diff of the diff locking system in a limited slip diff. Failure is very rare for these parts unless there has been incorrect oil used in a limited slip diff. Jeep diffs use a "C" clip on the end of the axle inside the side gear and it is possible that one or both clips have become dislodged and and become immeshed in the gears

This is a warning light in the diff that is telling you that the diff oil temp is outside operating parameters . It can be from low oil level in the diff , failing bearings , or simply an under inflated tyre ( flat) that is making the side gears work when they shouldn't be thereby generating extra heat for the oil

What makes a car AWD is the fact that there is a diff in the transfer case in the gear box . This allows the front diff and the back diff to operate at different speeds from the road surface just as one wheel can go faster in turns than the other side.. To say that the AWD is not working would mean that it is not going any where as the rear or the front will have no drive because the diff will not be operating as a diff.

there has to be constant all wheel drive because that is the drive train design. A diff at the front --a diff in the middle (gearbox) and a rear diff. If there is no drive to the rear diff then maybe there is a problem in the centre diff and the previous owner removed the connecting drive bit .

If the shaft is spinning thn theres nothing worng with the diff...(if i read right what you explained), the problem seems to be the drive shaft,probabely the splines at the front hud is gone or maybe the swivel joint has given up.

change out your diff locking selonid on top of your front diff