Thread: T/C leak,has anyone got a guaranteed fix.

Originally Posted by rick130

I can't believe I'm going to admit this on a public forum, but here goes....

That's OK, get it off your chest, that's what we're here for...

Well all the leaky T/C's are coming out of the woodwork now. Pat

I was musing over an improvement to the bush setup a while ago, the idea I came up with (as yet untried) was to make a threaded cap to screw in behind the head of the intermediate shaft. The head of the shaft would have to be reduced slightly in length, which shouldn't be a problem if it is bearing in a steel bush rather than the aluminium case. A screw-in cap about 6mm thick with a couple of blind holes for a 2-pin spanner, thread sealant for good measure.
If I can ever get through all the projects I have on the go, I will knock something up to see how the dimensions work.

This my thoughts on paper
Cross section of case Ishaft removed for clarity
4140 bush press fit with locktight to case (black).
Tight Slide fit cap with sealant around the flange.

I don't think the trouble of threading the flange is worth it????

Steve

Originally Posted by roverrescue

This my thoughts on paper
Cross section of case Ishaft removed for clarity
4140 bush press fit with locktight to case (black).
Tight Slide fit cap with sealant around the flange.

I don't think the trouble of threading the flange is worth it????

Steve

That'd work, a threaded end is becoming too complex for no real gain, but having a lead on the bush would help not bugger up the O ring on assembly.
I was probably going overboard, but I used a top hat section bush in the t/case too, and I really went overboard with the steel sandwich plate between the extended sump and case to prevent any (potential) case flex during high torque/load situations with the lower low range gearing. i think it was Sitec I pinched that idea from.

Originally Posted by roverrescue

This my thoughts on paper
Cross section of case Ishaft removed for clarity
4140 bush press fit with locktight to case (black).
Tight Slide fit cap with sealant around the flange.

I don't think the trouble of threading the flange is worth it????

Steve

I don't think that will fly- I'd have to have a a look underneath but I think the gearbox comes too close to the diameter of the shaft to have anything proud of the front of the transfer case.
Threading the bush would be a sight less work than pulling the transfer case out again to fix another leak; even if not, I'd rather spend a week making threads on the lathe than a day taking the transfer case out. I reckon positive containment is the thing to aim for.
And yes it is essential to have a lead-in for the O-ring.

The other possibility is to machine another o ring groove in the intermediate shaft. In addition to the steel insert that is required to prevent the shaft eating away at the case. Another preventative measure is to ensure the bearing preload is right. Ditching the solid spacers and going back to the old ways ie a crushable spacer is the first thing to do....

Jc

Justin I did think with a longer bush a second o-ring could be machined but with a cap? Meh!
POD I thought I measured at least 10mm of clearance - plenty room for this design???

S