340 diff removal

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Bobalob
Posts: 24
Joined: 20 Nov 2007 05:27 pm

340 diff removal

Post by Bobalob » 26 Feb 2008 07:29 pm

Hi,

ive heard when removing the diff on 340's the gearbox has to come out too otherwise its a bit of a job to set the diff up again? if you remove it from the box that is.

What exactly needs setting up when replacing a diff?

cheers

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mac
Posts: 1403
Joined: 19 Apr 2006 11:02 am
Location: Needham Market U.K.

Post by mac » 27 Feb 2008 02:14 pm

The "setting up the diff again" problem is actually setting the output shaft and countershaft (layshaft) preload (by calculating shim thickness reqd) of the gearbox - but this applies ONLY to the MT4 (M45R) four speed box. In that box only the preload shims are sandwiched between the bearings (in the gearbox case) and the diff case. You also need to take account of the fitted thicknesss of the gasket used.

If you have a 5 speed box (M47R) there are no problems and the diff unit can be removed/changed/replaced as a "bolt on" job.

Having said that it's probably just as easy to remove the g/box/diff as a complete unit and then seperate them rather than leave the box in. (you would have to support the box in the car anyway as the rear mounts are on the diff. Also you would have to lower the whole unit to extract the diff rearwards as the axle beam is in the way. The only "extra" work to remove the lot is removal of prop (two allen bolt clamps), disconnection of gear linkage (slide off sprung cover and remove pin) and removal of two bolts for the front support beam. If the diff is coming out all the rest need to be done anyway (driveshafts, rear mounting beam etc. etc.)

Have a look at my thread on my conversion of "Varts" 340 from 4 to 5 speed and the pix will give you a good idea.

Mac.

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Nikdev
Posts: 405
Joined: 08 Oct 2006 09:11 pm
Location: Norway

Post by Nikdev » 29 Feb 2008 12:28 am

M47:Just jack the car up and put it on stands, take of the diff lid off, unscrew the driveshafts, remove them and the diff is loose.
Take it out trough the hole then put in the new diff in, put on the driveshafts, lid and oil and drive away....

Easy job :D

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foggyjames
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Location: Nottingham, UK

Post by foggyjames » 06 Mar 2008 01:44 am

On a 340, I think Mac is exactly right - remove the box complete, then split it on the bench. On a 360, where removing the box is a much more lengthy process, I would suggest that the diff alone is removed...although that in itself has its difficulties.

cheers

James
VOC 300-series Register Keeper
'89 740 Turbo Intercooler
'88 360 Turbo Intercooler
'85 360 GLT
'81 343 GLS R-Sport
'79 343 DL
'70 164
...and some modern FWD nonsense to get me to work...

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