Removing front flex plate and gearbox seal

[WGB]

I will be replacing the gearbox output seal as it has a small leak and the front flex joint has oil on it.

All procedures I can see seem to show that the whole driveshaft has to be removed and if this is the case I wll replace the rear pinion seal as well but is it possible to only remove the front flex joint without removing the whole shaft.

Bill

 

[Styria]

Hi WGB, I spotted this thread yesterday - never saw it previously as I was in Europe at the time - or close to it.

The way I see it, you should be able to push the prop shaft back far enough to enable you to remove the front flexible coupling. There is a sliding joint connecting the two halves.

How about the output shaft seal - have you yet gotten around to replacing it ? From memory, you need to exercise care when re-fitting the extension casing. Cannot quite recall what it is - some part (speedo worm drive ?) needs to be 'MOVED' in order to refit the casing. If not moved, you can damage a 'CERTAIN' part. Sorry to be so vague - just exercise caution when re-fitting. In any case, you may not yet have done the job. Regards Styria

 

[Styria]

Hi WGB, almost three months on, and thanks to new discussion board features at members' disposal (VIEW OPTIONS - UP TO 200) going back to the early period of October 2008, I have come across your thread regarding removal of the front flexible coupling and replacement of the gearbox extension output shaft seal.

Did you ever carry out this job and, if so, did you strike any problems in particular ? With jobs like these, it is great to have the use of a hoist and gearbox jack, but it can still be a little awkward. Also, how about that CERTAIN part that I referred to ? I still can't quite remember what particular problem one could encounter, but caution needs to be exercised. Regards Styria

 

[TJ 450]

You shouldn't have to remove the extension casing, just the three-arm flange.

Tim

 

[WGB]

Hi WGB, almost three months on, and thanks to new discussion board features at members' disposal (VIEW OPTIONS - UP TO 200) going back to the early period of October 2008, I have come across your thread regarding removal of the front flexible coupling and replacement of the gearbox extension output shaft seal.

Did you ever carry out this job and, if so, did you strike any problems in particular ? With jobs like these, it is great to have the use of a hoist and gearbox jack, but it can still be a little awkward. Also, how about that CERTAIN part that I referred to ? I still can't quite remember what particular problem one could encounter, but caution needs to be exercised. Regards Styria

Hi Styria,

My problem with the car is that when is sits on my hoist for a few days (in a slightly tail down position) it will leak a noticeable amount of automatic transmission fluid onto the floor. During normal running and parking it doesn't spill a drop - but then it sits slightly nose down - and the transmission never needs topping up.

I purchased a new set of mounts - engine and transmission as the RH engine mount had settled allowing the air-con pipe to hit the frame on full throttle acceleration - as well as diff pinion seal and transmission seal and a new flex-plate but when I took a closer look the rear transmission seal was totally dry so I changed the two engine mounts (which were a little settled but not too bad) and the transmission mount (which looked in almost new condition but I changed it anyway) and left the seals and flex joints well alone.

I cannot find the source of the leak when it is on the hoist but notice it has done it again while sitting getting it's suspension re-built - a couple of tablespoons as a one off leak after sitting for a few days.

The (Plastic) vacuum modulator is covered in oil so whether this is the source of the leak I don't know but I do have a new one and will change it if I have time in this round of "improvements".

I have carefully re-torqued the transmission sump bolts and this joint is dry.

I have a theory that there is something leaky on the transmission that ends up below the oil level when in a slightly tail down attitude after the torque converter drains some of it's oil back into the auto after extended inactivity that is above the level when in it's normal position parked slightly tail up .

Bill

 

[Styria]

Hi WGB, if you ever want to establish whether your transmission is leaking, just leave the car unused for about three to four days. It is surprising how badly they can sometimes leak.

Of course, if it worries you unduly (in my case, anyway), simply degrease the box, blow it dry and go back after about four days and you'll soon see the source of the leak(s).

Modulator threads should be lightly smeared with sealant prior to fitting, so keep that in mind (you probably know that already). Another common source of oil leak can emanate trom the gear hold shaft - that seal , if leaking, can be replaced in-situ, but it's not real easy. Another source, of course, is your pan, but you have already eliminated this. Thus, I would suggest degreasing, washing and blow drying - that ought to do the trick.

Incidentally, the front pump seal, if leaking, requires removal of the box - again, I am sure you'd be aware of this. Just as a matter of interest, it is just about imperative to remove the torque converter in unit with the gearbox. If it isn't detached from the drive plate, removal could easily damage any number of components, such as the front pump bush, torque converter engagement dogs and the drive plate itself - not a smart scenario, but I am sure you'd be aware of all of that. Regards Styria

 

[WGB]

Thanks for the comments Styria.

Normally the oil loss is nil except when "sleeping" on the hoist and there are certainly no seal leaks visible.

I had actually forgotten about it until it's recent suspension strip down but will have another poke around when I get my suspension finished.

Bill