Sierra Diff Help!
tbox - 11/6/15 at 08:48 PM
Hi All,
I leant my car to someone with the mechanical sympathy of a crack-smoking rhino (it was his wedding and I was trying to be nice) and it's come
back with a cracked diff amongst other transmission issues!
It's a sierra LSD 3:62 and I was wondering what my options are...
1. drop it out and replace it? (in which case, is there an easy way of telling if I have a 7 or 7.5 inch version?)
2. drop it out and replace the casing only (in which case does anyone know where I would get a casing only from?)
3. drop it out and get it welded?
4. open a bottle of red wine and hope it fixes itself..
Thanks in advance for help!
Tbox.
CosKev3 - 11/6/15 at 09:09 PM
You can measure the width of the top mounting point to determine the size.
Depends where the crack is to how hard it will to weld,as the crack will need to be ground open a bit and needs to be totally oil free for the weld to
take properly.
Replacements are £200 if you land lucky on a bargain,but usually knocking on £300 now for a 7 inch LSD.
Swapping the internals is not a diy job if you've no experience.
mcerd1 - 12/6/15 at 08:19 AM
You don't have to measure it to know if its a 7" or 7.5" diff
7" ones use long through bolts on the top and bottom mountings like this
7.5" ones have short bolts in threaded holes like this
If your still not sure post a couple of pics and we'll be able to ID it for you 
If you have to pay someone else to rebuild it with a replacement case then it will probably cost as much as a decent condition replacement diff, but
its still going to be a better option than welding it.
I've got to ask - how did he manage to crack the diff casing?
They are normally bomb proof unless you have silly amounts of torque or there is a issue with the way its been mounted...
[Edited on 12/6/2015 by mcerd1]
Irony - 12/6/15 at 09:06 AM
Ohhh Shiny....!
bi22le - 12/6/15 at 11:09 AM
quote:
Originally posted by Irony
Ohhh Shiny....!
Is that what the english translation is of the red writing on the box?!?!
gaz_gaz - 12/6/15 at 11:28 AM
If you need a 3.62 7" lsd with 100mm joints then i have 1 I've only just got hold of but change of plans means it's now not needed,
£230 plus the postage which is what it cost me.
Also have a brand new tran-x with again, Brand new, 3.38 crownwheel and pinion
cheers
tbox - 13/6/15 at 11:14 AM
Many thanks for all your helpful responses. from the pics I can see I have a 7" on there at the moment. Gaz-Gaz I will U2U about the diff you
have for sale.
all the best,
Tbox.
craig5 - 13/6/15 at 08:48 PM
if not sold diff i could also be interested
tbox - 14/6/15 at 08:37 AM
quote:
Originally posted by mcerd1
I've got to ask - how did he manage to crack the diff casing?
They are normally bomb proof unless you have silly amounts of torque or there is a issue with the way its been mounted...
[Edited on 12/6/2015 by mcerd1]
Now that is a VERY good question!
I have no idea at all at the moment and probably won't until I get the rest of the bodywork off (a job I started yesterday) and the petrol tank
out as well. from what I can see from underneath, one side of the top fixings has sheered off. I suspect the cause of this might be the way I fixed
it. because of the way the chassis has been designed, it was not possible to thread a rod all the way through, so i had to put a bolt inside each end
and then wind a nut on the outside. clearly not how the thing was designed to be mounted but the only option I had...
once I get her clothes off I will think about constructing a more elegant solution to fitting!
all the best,
Tbox