Pajero 1997 transfer case front oil leak

[giacomo.m]

Hi all,
I am owner a Pajero V24W 2.5 TD 1997 with a boring oil leak from the front drive shaft
this is third seal in many months....
yoke of the tail shaft is ok no groove :36,00 mm

I seem to have read that there is a welch plug in the end of the front drive shaft that shifts or deteriorates
where exactly is it ?
is it difficult to replace it ?
I ask for your help maybe even with some pics
thank you


Giacomo

[nj swb]

Hello Giacomo,

When I read your thread title my first thought was the welch plug - I've had mine leak twice.

Where is it?

The output of the transfer is a splined shaft, which mates with splines inside the front yoke. To form the splines inside the yoke a broaching die is pushed through - all the way through, which means the hole must be a through hole. A welch plug is then installed at the end to seal the hole.

This welch plug develops a leak.

Once the yoke is out and the universal joint is removed it's very easy to see the welch plug. When mine first leaked I was advised to seal it with epoxy, rather than try to replace it. Give it a good clean / degrease, set it somewhere firmly (I used my vice), level it up as best you can and fill to the brim with epoxy resin - I used a 2 part epoxy glue, left it to set for 24 hours, and stopped the leak.

For a few years.

Second time, I was on a trip and had no choice but to replace the entire yoke, with a second hand part from a wrecker. The replacement part hadn't developed any problems when my NJ was taken off the road.

To "seal" or replace?

If you replace the welch plug, have a good look to determine why the plug is leaking. If you have corrosion inside the hole a new plug may not seal any better - there's probably some sealant you could use with the new plug.

If you try sealing the existing plug, do some research on suitable sealants - an epoxy may not be the best solution.

If you try epoxy don't try to "rush" things with a fast setting epoxy - the fast setting versions can soften again at elevated temperatures. I've been advised that some of the "5 minute" versions will begin to soften at 60 degrees C, which I would expect the yoke to exceed in normal operating conditions.

Good luck.

[giacomo.m]

Hello nj swb,
thank you for the great advice, but basically how do i remove the welch plug ?
do i have to remove the metal dust cover ?
and maybe you can not do a welding to solve the problem permanently ?


Giacomo

[bige]

Hello nj swb,
thank you for the great advice, but basically how do i remove the welch plug ?
do i have to remove the metal dust cover ?
and maybe you can not do a welding to solve the problem permanently ?


Giacomo

you have to dismantle the uni joint to get to the welsh plug on the end of the yoke
its a steel plug so yes it can be welded
ive welded a few of them

[nj swb]

Hello nj swb,
thank you for the great advice, but basically how do i remove the welch plug ?
do i have to remove the metal dust cover ?
and maybe you can not do a welding to solve the problem permanently ?


Giacomo

OK, I re-sealed mine (the first time) over 15 years ago, and I've consumed much red wine since then.

You need to pull the shaft, which means draining the transfer case - it will leak oil once the shaft is removed.

I think the dust cover just knocks off with a few gentle taps from a hammer - some form of "soft" hammer would be a great idea. Then remove the universal joint, and the welch plug is about as accessible as it ever will be. To remove, you'll need to "drift" it out from the inside of the yoke.

Welding? Personally, I think welding would lead to a world of pain. If the welding doesn't do dastardly things to any oil remaining between welch plug and yoke (I think I'm on another continent - I reckon I'll be safe ) you run the risk of having the heat create a distortion in something that needs to be perfectly balanced to spin at several thousand revolutions per minute. I'm sure it can be done, but I expect it's much trickier to get right than most would realise.

Replacing the welch plug with a suitable sealant (no idea what that would be) is (in my opinion) the most reliable fix (least risk of failure in the short term and the long term).

A good degrease and re-seal with epoxy or similar should "kick the can down the road" for a few years - longer, if you do it better than I did. I'd say easiest / least risk in the short term.

Welding? Least likely to work. If you can make it work, I'll be impressed!

Edit: Bige posted while I was typing. I'm impressed that welding will work - but then again, nobody is impressed by my welding...

[giacomo.m]

Thank you nj swb


but how did you solve the problem ?
welding or epoxy sealing ?


Giacomo

[giacomo.m]

Hello nj swb
found the cause of the oil leak
had been put some sealing paste, now I see whether to weld or seal with epoxy resin


thank you


Giacomo