Hi everyone. Well I've been having some problems with my tranny (As I mentioned in a past post) and wonder if it's more than just the tranny. Maybe it's the electrical parts on the OD. Where are the relays and such located that control the OD? My problem is this, sometimes it just won't engage- the light on the dash comes on (the '5') but it just doesn't even try to ecgage sometimes. I've tried pushing the shifter to the back of 4th to see if that helps (if it's the switch) but it doesn't. At some point it usually just engages. Other times I'll be driving along in '5th' and it's fine and when I let off the gas just to drift it just slips into a neutral state and the engine drops to idle but then when I press on the gas it's in 4th and usually slips back into OD. A couple of times after driving pretty fast (90+) when I let off the gas it slips into 4th (thus making the engine rev way up higher than I'd like, in shich case I go to neutral to save the engine). Does all this sound like the same problem, or a combination of problems? Anything I- the slacker shade-tree mechanic- can do?
Thanks

Three potential problems after the fluid level is checked. Low fluid will cause most of the problems you are having.

Sticky solenoid and/or failing actuating piston seals. The sticky solenoid will cause a no engagement situation as will a loose dirty terminal on the solenoid(number 3).

Step one.
Once the fluid is up to full, and while you are down there anyway, check the wires to the solenoid on the left side of the OD unit. Remove, clean, tighen slightly and reinstall. With the engine off, ignition on, gear in 4th andOD on,(dash light on), wiggle the sires oncluding the ground side. You are checking for broken wires inside the insulation. If the solenoid clicks while you are doing this, verify a tight connection first then ccheck for the broken wire.

Step two.

Remove and clean the solenoid. You will need instructions so e-mail mme for a set.

Step three.

The actuating piston seals are beginning to fail. This would require removal of the OD from the tranny to replace. Same time and work as replacing the present unit with a used unit which may have the same or worse symptoms, but does not cost as much since you already have the tranny and OD. Plus you do not have to install the used unit to find out if there is a problem which you would have to remove to repair.

Duane

Thanks. I did a search (as per Alex's suggestion) for your posts and have found them quite helpful as for things to check. I don't think I'll be able to get to it until this weekend. I'll be emailing you if I get so far into it as to need the further instruction. To start, I'll drain and replace the fluid, then I'll check the wires at the solenoid.
Thanks again.

--Ben

Hi all. Well, I tried the 'electrical test' as described and both things seem to be working (click anyway) so I must get into it more and replace o-rings and the oil and hope that helps.
Thanks everyone.

What type of fluid are you using, and what sort of condition is it in?

Yeah, the clutches wear out eventually.. but low, old, or the incorrect type of fluid can contribute to problems.

I'd recommend you check the brickboard and (more importantly) the swedishbricks archives. Duane, the laycock od guru, has contributed quite a bit of useful information if you decide to go it on your own.

Given that a junkyard will probably charge you the same for an OD unit and an transmission+OD unit. It's probably worth just replacing the whole thing rather than spending the effort rebuilding the OD. Your call.

- alex

'85 244 Turbo
'84 245 Turbo

Well, I've never replaced the fluid since I've had it and by the way it seems to have been maintained it's quite likely that it hasn't been replaced in some time. When my mechanic was checking it out they said it was low a quart so they replaced it, but they didn't a) drain it all out or b) tell me what kind they put in. I'll figure out how and replace it, maybe do the seals at the same time. I'll scan through the Bently and see what kind of help it is. What fluid is recommended?
Thanks

The easiest choice is Type F Automatic Transmission Fluid. You've also got a host of synthetic options, and extreme climate (which wouldn't apply to you) dino options as well.

If your fluid is low (I believe you can just stick your finger in the fill hole), that would cause various OD engagement issues (and possibly lasting damage).

If you feel inclined to drain it, make sure you can loosen the fill plug first.

- alex

'85 244 Turbo
'84 245 Turbo

If it works better when cold, and when going at high speed it is likely the seals on the actuator pistons. Pretty cheap parts but a real PITA to replace. I am waiting for the snow to go so I can replace the seals on mine. I can only keep it in 5th going over 120km right now.

The solenoid is down on the tranny. Has two wires going to it. With the engine not running, put the trans in 4th and operate the OD button. You should be able to hear the OD relay click behind the dash next to the glove box. If you glisten down near the trans while someone operates the OD button, you should hear it click. If you do, the electrical system is probably ok. The solenoid could be in need of new O-rings but I haven't had to do that yet.

I did have an OD in my '86 act like yours. I drained out the old oil in the tranny and replaced with REdline MTL. I tilted the car up on the left to allow me to overfill the tranny like we do with the M47 tranny. Anyway, the OD started working like new again. I think that I've only borrowed time before I have to put new o-rings into the OD but it has worked fine for nearly a year now. If you try a search in the archives you'll get lots more info.

Very good instructions- I'll have to try that soon. I think I have a leak somewhere on the tranny, but not sure where. I should drain the oil and replace it too. Thanks

it might be the solenoid. If the light on the dash comes on then it's probably not the relay or the switch.

Probably a stupid question, and I'm sure the Bently could tell me- where is the solenoid located?
Thanks for the responses

in my case it was a worn out housing bores that was not holding hydraulic pressuer on the pistons that keep it in OD. Mine started out like yours but I kept driving it as it got worse and worse.

Would fall out of OD into 4th as I rounded exit ramps and on ramps. Got worse and worse and finally would not hold 5th at all after the oil in the tranny warmed up.

There is a kit available that lets you replace the O-rings on the various pistons in the unit but that did not help mine. I finally replaced the whole OD unit with another from a junk yard.

Try the electrical route first, though. Make sure the solenoid is working. It directs the pressure to the right passages to hold it in OD.