[6pack] rebuilt differential on Ebay

[Robert M. Lang]

Hi,

TR6 diff rebuilds are fairly straight-forward, but if you don't have the 
special tools for setting / measuring the pinion head height, you have to 
resort to an iterative process to set the height and then you have to set 
the bearing preload (or visa-versa... it's in the manual.) The general 
point is that when you get it wrong (which is fairly likely), you have to 
pound out the bearing race for the inner pinion bearing (aka the pinion 
head bearing) and insert / remove shims to get thing in line.

Now, you could "relieve" the outer race for the pinion head bearing so it 
doesn't have to be an interference fit, but there's enough tolerance built 
in that you could set the shims and the bolt it together and things are 
too tight (or the ring gear meshes oddly with the pinion) and you have to 
pull everything and adjust after you install new bearings.

Bottom line, there can be instances where you pull the entire thing apart 
5 or 6 times to get the shims right. My experience in these situations is 
that you also wind up sacrificing some shims to get things working okay, 
so that adds a bit to the expense, e.g. buy 4 of this and 4 of that and so 
forth. There's two sets of shims, the small ones for the bearing preload 
and the big ones for the pinion head. So the cost of the shims adds up.

But if someone is offering a truely reconditioned diff for $500 or less, 
it's a pretty good deal. On the other hand, the pinion and ring gear are 
one of the weakest parts on a TR6 and if the reconditioned diff ever ran 
out of oil or overheated the gears are probably toast and prone to 
failure... my personal preference is to recondition AND replace the gears. 
Then you get a very long service life as long as the unit is never 
overheated or run out of oil.

So, if you have the time and the inclination AND THE MANUAL, you can go 
for it. But also make sure your fore-arms are nice and strong 'cause you 
get to do a lot of pounding in this job!!

Note that removing the center section of the diff is pretty easy even in 
the absence of a case spreader. I've done MANY of these without a case 
spreader and it's really quite easy to get that puppy out as long as you 
move it a little at a time on each side.

Figure a min. of 4 hours for this job, maybe longer depending on your 
skill level. Take your time and don't force anything and make sure nothing 
binds when you're putting things back together.

It's you call.

rml
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Bob Lang              Triumph TR6!!            |  This space for rent
2009 NER Solo Chair                            |
Voice:617-253-7438                             |  Cell: 339-927-4489
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