Don't like the adverts?  Click here to remove them

Porous rear diff???

chadr

Well-Known Member
Joined
Mar 19, 2010
Messages
3,242
Garage
Country Flag
england
I've noticed an oil stain on the back of the rear diff - it spreads around most of the rear side (above and around the filler) and covers the bottom of the diff - hopefully pics will show what I mean...and it might just be leaking from the filler.:think:

I've tried to check the oil level but am struggling to get the filler off - I really need a 6 sided 23mm socket to prevent rounding it, as the standard socket I have just slips. :crazy:



The rear diff and components were bone dry when I had the Crown rust protection applied and now that it has dried off, apart from this area, the rest of the surroundings are still dry.

 
Last edited:
The Diff on my old Colorado was so thin oil would seep through the Metal, Bugger to weld up, My 120 is not much better ... But the 30yr Old 80 is still as new.....The filler and Drain plugs can be a pain, Not enough recess for the Socket... Crap design that one..
 
0D994DB0-77E7-4691-A7AD-EA24521F0ADB.jpeg
I ground off the end of my 24mm deep socket for diff plug
 
Do yourself a favour and order a new filler plug.

Your leak looks a little bit like it's coming from the plug and might point to a dodgy sealing washer, but it'll be a good idea to get a new plug anyway if the original is getting rounded off.

If the diff has become porous, you may be able to get someone to weld a plate over it. My garage called in a favour from a welding specialist, who put a stainless steel plate over the bottom and was able to do it in situ which saved me some money. Fantastic upgrade for off-roading as well as curing my porous diff.
 
Thanks for the responses guys - much appreciated. :thumbup:

I'll order a new filler plug and washer and get them replaced, along with checking the level.

I suppose it's a case of wait and see, once that's been done. :shifty:
 
I got a 23 and 24 6 sided if you need it
 
Don't like the adverts?  Click here to remove them
Thanks Nick - I'll drop you a line tomorrow mate. Cheers.
 
No probs. Just got my shopping to do in morning but free after that
 
My deep 24mm socket from Halfords fits perfectly no grinding required
 
Mines a Halford pro socket and it had a small bevel which gave little purchase on such a shallow bolt head when it was rusted in and ruined , grinding the bevel off let me hammer it on to grip the base of the hex head .
 
Grinding down a socket is one of those amazingly helpful tips... I've never needed to with mine, but wouldn't hesitate to do it for a second if my plug was getting too rounded. I agree that these are a slightly weak design.
 
Update.

Finally got around to removing the filler and drain plugs*. Only had about 300ml of oil in the diff - WTF!! :shock:

Anyway, replaced both drain and filler plugs with new items and used PTFE as suggested. Filled up to filler level (approx 2l?) with oil and then degreased the previous leaks and gave the diff a good wipe over.

Had some errands to run, so after about 12 miles and a couple of hours, this is the state of the diff;



I think it's safe to say that I have a porous diff :thumbdown::thumbdown::crazy:

* Thanks Nick for the lending the socket and bar - even though I didn't need it in the end. :thumbup:
 
Last edited:
Its exactly how mine was, I did manage to weld it up but it was hard work.. The steel is so thin. Trying to grind back to get something to weld to, And the Ingress of oil doesnt help.... Patience and the help of CT1 or Tiger seal. Its a shame you cant buy the Diff bowl . Cut the old one out and weld in the new Like LandRover... I did look into it But it was a No No! from Toyota...If you do go down the CT1 or tiger seal Route. It really has to be completely clean of any Oil....
 
Thanks, that is certainly one option.
I'm going on holiday end of next week, (not driving), so will put all the truck issues on hold until I get back and will do some research in the meantime.

Thanks for the feedback
 
Thanks, that is certainly one option.
I'm going on holiday end of next week, (not driving), so will put all the truck issues on hold until I get back and will do some research in the meantime.

Thanks for the feedback
It's worth pulling the axle out and givit it a proper check. Looking at your photos I wouldn't be surprised if spring seats and top arm mounts aren't worse for wear too.
 
You can't break what's already broken so get one of these https://www.screwfix.com/p/non-woven-preparation-wheel-115mm/83915?tc=UT4&ds_kid=92700022885054691&ds_rl=1241687&ds_rl=1245250&ds_rl=1244066&ds_rl=1248184&ds_rl=1245250&ds_rl=1247848&gclid=EAIaIQobChMIuem_oMvE4wIVgrHtCh13JAMGEAQYCCABEgJf1fD_BwE&gclsrc=aw.ds for your grinder and you will be looking at shiny new metal in 5 minutes without being overly aggresive so you can see whats what before making any decisions , that done maybe a blob of this stuff https://www.ebay.co.uk/i/312224432964 will buy you some time .
 
Last edited:
No idea how much that replacement axle casing is and it’s certainly a lot of extra work but it has to be a preferred option. With the metal so thin and pin holed that it weeps oil, any repair including welding will be a temporary one.
Externally the spring seats and, particularly, the control arm turrets can look all fine and dandy when painted up but they corrode from the inside out.
 
I've done a couple of these, new axle casing and 2 inner axle oil seals, one days labour and everything else should swap over. The only real tricky bit is if the difflock actuator will come out without an issue. I would probably budget for a new set of diff studs and nuts to be on the safe side.
 
Back
Top