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At last - I have found the problem with my transmission.

Fingers really are crossed for a super quite drive after doing this. I was scared of building a front diff, but actually now I realise whilst not something to mess with if you are clueless, you CAN do if you're at least a halfwit.

How the hell does Ben take pictures when he does all of this stuff. I just don't have time nor patience.

That rules me out then Chris :lol:

I've no Idea how Ben does it, I've had a go on a small scale and it drove me potty!
 
I just think about what I'm going to write, while I'm doing the job and then take pics around what I'm going to say. :shifty:

Nice work finding the culprit of the noise Chris. :icon-wink:

Good luck with the diff rebuild. :icon-biggrin:

If your not already, buy/make yourself a solid spacer for the pinion rather than a crush tube! That way if the pinion bearing ever fails it wont shear any teeth of the ring gear.
It also means when changing the oil seal you can torque the nut back up without risk of crushing the crush tube more/altering the position of your pinion against the ring gear. :icon-ugeek:

Another thing worth noting is check the ring gear really carefully for hair line cracks before fitting it. My 70's run the same front diff as the 80 and I've found a few hairline cracks in ring gears over the years. :doh:
 
Triple check you put oil in Chris. I double checked after one of my rebuilds and confidently drove off without oil. After a noisying return to the garage I took the level plug out to check the oil level for the 3rd time and hot and angry paraffin steam came out.
 
Frank these holograms are not fake and I can prove it because they have a hologram on them showing that they're genuine holograms

Forget to put oil in? I think not.
 
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Well I have twatted about with this diff for hours and hours. I can get all of the tolerances right, just not all at the same time. It's a good diff so no suggestions about swapping it please, but I am just chasing settings round and round. I can get the pinion pre load right. I can get the carrier pre load right too. I can get a fair pattern on the teeth, not perfect but close but only with a black lash of .50 instead of .13 to 0.18. Depth looks right across the teeth but I think I need to play with some pinion shims to see if I can get it centralised. So any way I kicked it onto touch and started making this instead.

Made a spindle


Screen Shot 2016-09-04 at 17.42.29.jpg


Fitted a sleeve

Screen Shot 2016-09-04 at 17.42.38.jpg


Attached the diff like this

Screen Shot 2016-09-04 at 17.42.48.jpg


so that with a quick flick it does this

Screen Shot 2016-09-04 at 17.42.58.jpg
 
They're just such a damn awkward thing to put in a vice Flint. I usually use wooden packing so that I can get it tight in the vice without it slipping. But it's a pain. This is partly a prototype and will only fit this diff. It needs to be strengthened a bit as it's slightly springy but for just doing the repetitive jobs it's handy.
 
It's a good site I know but it doesn't help tremendously. I'm struggling with peripheral bits really like the marking paint. I bought some but it just doesn't give a nice clear pattern like that. I managed to borrow a micro torque wrench so at least I can measure PPL accurately now. It's not that I don't know how to do this, it's just that I am not getting the results that I need so far. Tonight I have to say I have got it close enough I think. A few more checks and hopefully if we have a decent weekend, I'll put it back in the truck.
 
Post some pics of the gear drive pattern if you got some.
Would be interesting to see...
 
I'll try, but it's hard enough to see the pattern in this grease stuff as it is. The WSM for doing the diff is actually very clear and it's not really a hard job to do. But you do need a press and the right tools lying around. Also having the ability to make special tools really helps. Some only need a drill and a bit of steel - it's not necessary to have a full workshop, but it's not something you could physically do without some kit.
There a goods many 80 owners out there with noisy front diffs I know. All I can say is that in the main, they're unlikey to let go. They're very strong and even with my de-laminated bearings, I've done 10K at least on them. Hopefully once back in, all I am going to hear is silence. I've driven other 80s with good diffs. I've owned 80's with good diffs and even for a old car, they're quiet. This one really has been a noisy blighter.
 
I also had no noise issues just too much backlash in the drive train. Worn bushes, CV joints, drive flanges, could be all contributors to that though.

About to take my front diff apart to check the bearings, as it's been running in grease instead of oil.
Backlash on the front diff is 0.32mm (0.0126")
 
You done very well Chris to diagnose the problem. So happy for you being relieved & looking forward to seeing is all back together. Gearboxes are usually very hard to repair so well done.
 
It's a good site I know but it doesn't help tremendously. I'm struggling with peripheral bits really like the marking paint. I bought some but it just doesn't give a nice clear pattern like that. I managed to borrow a micro torque wrench so at least I can measure PPL accurately now. It's not that I don't know how to do this, it's just that I am not getting the results that I need so far. Tonight I have to say I have got it close enough I think. A few more checks and hopefully if we have a decent weekend, I'll put it back in the truck.

Just skimming through this Chris, when you mention 'marking paint' issues, do you mean engineers blue or proper name Prussian blue? There are two types, a marking blue which dries and a non drying for setting things like diff lash, try getting some of that, makes setting diffs a lot easier.

regards

Dave
 
The noisy diff on the bench was due to bearings having no face left on them. The noisy diff in there now is noisy due to the corrosion pitting in the face of the teeth.

Dave, the stuff is a specific gear teeth contact pattern product. Really it's a sort of bright signal yellow grease. I've been thinking I need to get some Prussian blue. All of the pics you see have a sort of yellow chalk looking compound. This is certainly not that and isn't doing it for me.
 
Yep used the yellow stuff my self, but it was years back when setting up ARB lockers in my Land Rover Discovery, either I was using too much or what I don't know, it seemed to smear and not really show a good clean contact, I seemed to be chasing my tail getting the running contact right. I changed to Prussian Blue 'paste', this is different to the marking blue which dries in a few seconds, and I have no understanding why but, it seemed to show a cleaner contact area, perhaps because it was not so 'gloopy' (technical term) as the yellow contact paint.

regards

Dave
 
Dave, exactly that.
 
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