Crank shaft seals

[Bluebottle]

Having recently evacuated its entire contents onto the road after a test run i need to replace the rear crank shaft seal (unfortunately the engine was over filled at some point due to the dipstick guide tube being damaged so someone over filled it by at least 3 litres due to false reading from the dipstick .
Do i need to replace the rear bearing cap cruciform seal as well as matter course?
also, I plan on doing this by dropping the gearbox out on the drive with the car on axle stands...are there any pitfalls?, are there things I should be aware of other than makeshift mandrel to get the seal on to the crank shaft?

[caduceus]

I've only done this with the engine on a stand, and it was hard enough then. The main cap was a bit of a tight fit! The only advice I can give, is the seal goes in dry (outer perimeter). The cruciform seals may bulge a little out of their recess. Mine did, by about 3-4 mil. So I just cut them off flush.
Other than that, good luck!

[ClassiChimi]

Get some old paving slabs (or similar) and slowly raise the car up until you can get your jacks as high as possible, and yes replace cruciforms.

[phazed]

You can use a little weak locktight on the seal.
Also use a good gasket sealant as well as the cruciform seals.

Beware cheap pattern cruciform seals, ensure they are a good make. Many inferior ones shrink!

[Steve_D]

The rear crank seal can be changed without disturbing the rear main bearing, cruciform seal, sump etc.

Simply dig out the old seal, clean the housing and fit the seal.

I've been in a debate elsewhere on here about whether the seal should be oiled or dry. For any other similar seal I would use oil but there have been a number of examples with this particular seal where it pops out again if oiled. In one case it popped out overnight with the engine still on the bench.

I've done a number of these now and just tap them in dry. If you try and use some sort of drift (like an oversize socket) it is difficult to see if it is going in square so just keep tapping around the seal until it is home in the housing.

Steve

[Bluebottle]

thanks for the responses Chaps .
Steve, the outer rim of the rear crank seal should be fitted dry as it is a push fit seal, only the the inner lip should be oiled to prevent it snagging as u slide it in. (according to the Haynes and LR Overhaul Manual anyway).

[phazed]

I would still do the end cap and new seals.

When my old chim was leaking, the cruciform seals had shrunk back and they were only a few months old!!!

[Bluebottle]

phazed said:

I would still do the end cap and new seals.

When my old chim was leaking, the cruciform seals had shrunk back and they were only a few months old!!!

yeah i think i will, the sump pan will be off so seems prudent to do it whilst i am there

[Sardonicus]

phazed said:

I would still do the end cap and new seals.

When my old chim was leaking, the cruciform seals had shrunk back and they were only a few months old!!!

What Peter said fit seal dry, no need of fear of cocking the seal or the reinforcing spring jumping out etc as you tap/drift the new seal in because using the belt and braces main cap removal method you can locate everything as you nip up before final torquing never does any harm to look in the sump occasionally either checking pick up for debris and the 2 fastener security etc

[BoostedChim]

Sardonicus said:

What Peter said fit seal dry, no need of fear of cocking the seal or the reinforcing spring jumping out etc as you tap/drift the new seal in because using the belt and braces main cap removal method you can locate everything as you nip up before final torquing never does any harm to look in the sump occasionally either checking pick up for debris and the 2 fastener security etc

I recently changed my rear seal and crucifixes but it think I'm going to have to do it again as it's leaking worse than ever. I used the new style cross seals from Powers and fitted them with a smear of oil and some RTV on the top edge of the main cap. I fitted the rear seal after torquing the main cap. I'll give your method a try but I think this time I'll use some VW sump sealer on the top of the main cap and down the middle of the crosses.

[Boosted LS1]

I use anaerobic sealant on the main cap to block joint face. It never leaks when using this stuff. It's also used my some manufacturers on timing covers without gaskets.

The crucifix seals should be left proud by a few mm's as opposed to trimming them flush. That's always seemed a bit odd to me.

I fit the rear crank seal dry but oil the lip. HTH.

[Sardonicus]

Agree with above I would never fit those cruciform seals without a sealer personally to back the joint up