Discussion in 'E36 M3 (1991-1999) and E30 M3 (1986-1990)' started by JaseH1984, Aug 1, 2018.
I've had to order the gasket as that was in bits. I'm guessing the joint gets fairly packed with grease as there was a lot in there.
I'm gonna get the seals changed out over the weekend and get it all back together. I have found a PDF of torque specs and have ordered a torque wrench.
A question I have though. I have ordered new E12 Torx bolts for the half shafts. Do these bolts, (and all other bolts in general) require any form of grease prior to fitting, or should they be installed dry?
I have seen varying opinions on this regarding not greasing threads for friction, and greasing them to help with removal / corrosion prevention etc.
I have various bolts out now, boomerang, front diff mount, ARB bolts, exhaust hanger, and wasn't sure if they need any grease or lube before going back in.
Don't grease your bolts unless they're specifically intended to be lubed which is a very narrow set of applications. Lubing them also changes the torque spec and I'm not sure how you do the calculations.
So I’m guessing none of the bolts associated with the diff removal need to be lubed. Not sure where I’d even find that info.
I've never heard of them being lubed and the expert that did mine never mentioned it and we discussed it a fair bit.
Second question: https://www.newtis.info/
Some gunk engine degreaser did a pretty decent job at cleaning the diff up. Did the axle seals last night, but struggling to hold it still to undo imthe input nut.
Does anyone know if the 8 bolts which hold in the axle seal casings require torque? They came off easy enough so I’m guessing it’s not much, but can’t find torque specs for them. I feel wary about putting it back in the car with guesswork on the bolts.
don't lose the snap ring in pic 3 into the diff or you will be in a whole heap of pain...... that should have a replacement in the parts you bought!
Looking good though and well done for getting it out
apparently 22 NM, for the bearing cap screws depending on type, or 10 NM plus 40 deg......
BTW this website is your friend as well.... and has torque list at the end. There is an annoying pop up requesting donations which you have to shut down every couple of clicks but you kinda get used to it....
Perfect cheers. The snap rings, o rings and seals are all replaced, and those caps back on. Just need to torque those bolts then onto the input nut and flange removal. I have the nut and shaft marked for reapplying, however I’m going to have to find a way to lock it still to get the breaker bar on the nut. I haven’t got a vice and sticking lengths of wood through the bolts trying to lock the axles wasn’t cutting it, as it wants to lift up and flop in all directions.
I have the input seal, clamping bush and replacement spring washer still to do then it’s fit back together and fill with oil. It has taken longer and cost more than I would’ve liked, but first attempt, and at least I have the tools now for other jobs that will definitely arise!
Not sure where to start with angle torque. I have a wrench that will apply up to 210Nm and that’ll have to do.
Those bearing cap screws. Are they supposed to have loctite 270 applied? If so that’ll be another hold-up whilst I get some of that.
Dude, hats off for being detailed, but any red loctite will do, though i mostly use medium or low strength as its a pain if you need to re strip.
As to locking the diff i use a rattle gun but i have done it with wood in the output shafts, you need to stand on the diff hanger when you swing on the nut.
re angle torque you can use a angle gauge, (cheap) get a wrench that does angle (no cheap) use a protractor and a paint pan (cheapest) if however your wanting to torque the the input bolt, do not aim for the torque spec. you will screw up the contact patch of the gears, just put the bolt back where it was. there is a locking mechanism it wont come loose.
for the side caps, just nip them up 22NM isn't anything special tightness wise. something akin to reasonably tight with a normal spanner. I would doubt if you have a Tq wrench which goes upto 210Nm that it will go that low. So go for spanner tight.
Success! I put a bar through two old bolts in the flange to lock it and it came off quite easily. 9 and a 1/2 turns.
My wrench starts at 30Nm but it appears you can set it less. I’ve torqued them up now and yes it took very little pressure for it to click. Happy that they are all equally tightened now.
Now to crack on with the clamping bush and input seal. How Saturday nights have changed!
Hmm after taking the input seal out, I think I may give the clamping bush replacement a miss. Not sure I want to risk damaging this
Dude, seriously, stop. the clamping bush is whats commonly reffered to as the crush sleeve.
This is what sets to crown and pinion contact patch, to replace it you wouldhave to remove the entire cluster, press the pinion shaft out, press the inner bearing from the pinion shaft, then completely reset the gear mesh and measure the drag and contact.
Setting the contact patch is one of, if not the most complex part for rebuilding a differential, and its completely unnecessary unless you want to fit a new gearset or replace the bearings, even then i would first try and use the original.
Yes I gave that a miss. I did order the part but I have only replaced the seal and that will do. As for torque on the input nut, I marked the nut and shaft with a centre punch to realign them again. I did see on another forum that the torque for the nut was 140ft-lb. When I was tightening it back up with the breaker bar, they were so close but not quite realigning. I set the torque wrench to 140ft-lb and gave it a good go, it moved the nut very slightly then clicked, and now they are perfectly aligned so I guess it worked.
If i put it back in the car and it whines or leaks I will probably cry, I have been very careful to ensure everything was done as accurately as possible.
Re the loctite. Is this a huge deal to have it? I have put the bearing caps back on and torqued them, and reinstalled the axle flanges. Will I get away with it or should i be opening them up again and applying loctite?
re locktite, nah, its got a retaining clip anyway.
I only ever use thread seal grade on this type of stuff as if you need to break it down in the future red loctite can be a nightmare.
I wouldn't worry about it.
Cheers, I will update whether it has went well or terrible when it's back in the car and i've had it out for a test drive.
Not sure if it's an issue but i took both output bearing caps off one after the other (rather than change one, put it back, then remove the other). When I took off the second one the assembly inside the diff dropped and had to be lifted back up to refit the bearing caps. Hopefully this isn't anything to be concerned about.
It's all back together and seems to be turning smoothly. Fingers crossed...
nope, as long as you put them back on the right sides and any shims went back in the right place its fine.
You dont actually need to remove them to replace the seals.
Yeah I did think that. It’s a learning for next time however it has allowed me to give them and the bolts a thorough scrub up.
It’s all back together and ready to go into the car. I’m picking up the gasket that goes between the input flange and cv joint tomorrow as that was in bits, then I’ll get it all connected back up.
I got a new securing washer to go over the input nut, I’ve tapped it in and it’s not wanting to go any further without most likely mis-shaping it. Does this look far enough?
Diff before and after. Ready to go back in