[TR] OK, the IRS differential is shot. Now what?

[Ben Zwissler]

Unless you've got some experience with gearbox's or diff's, I'd pay 
someone to rebuild it, but R&R it myself.  Removing is purely a nuts and 
bolts job.  Flange bolts at the three input/output shafts and the nuts 
that fasten it to the car.  You'll need a floor jack to support it while 
you loosen the attachment bolts and then lower it.  I don't know that 
you'd have to have a British Car shop do the diff rebuild work.  Any 
tranny/diff shop should be capable.  I don't see anything unique about 
them.  They'd probably let you source the parts since they won't want to 
mess with finding them.  If you remove it and open it up you may be able 
to tell visually what's gone bad and then look up the parts cost.  Plan 
on new bearings regardless of what gears may be bad.  I've often found 
that bearings can purchased cheaper at a local bearing supply place 
(Bearing, Inc. around here) - they're often standard sizes.

Looks like TRF does the rebuild for $1,300 - not cheap.  I've done seals 
and minor other repairs which just take a gear puller and maybe a case 
spreader.  I've been lucky and not needed a case spreader for any I've 
done (MG Midget, TR4A and TR8).  The most complicated job I did was 
replacing the limited slip clutch plates in the TR8's Salisbury LSD 
unit.  If you need a new pinion/ring gear that takes a little experience 
to get right.  You'll also need a dial gauge, but those are cheap these 
days.  All I did to my TR4A diff was to replace all the seals and 
luckily its been fine.

Anyway, my two cents worth.  Others feel free to disagree.....

Ben....


Ben Zwissler
bjzwissler at gmail.com
Columbus, IN
1966 Triumph TR4A
1973 MG Midget
1980 Triumph TR8
2007 Mazda RX8
2002 Yamaha FZ1
2003 Honda ST1300
2005 Harley Davidson VROD


On 8/11/2010 11:05 PM, triumphs-request at autox.team.net wrote:
> Date: Wed, 11 Aug 2010 18:59:46 -0700
> From: "John&  Pat Donnelly"<pdonnel1 at san.rr.com>
> Subject: [TR] OK, the IRS differential is shot. Now what?
> To:<Triumphs at autox.team.net>
> Message-ID:<003201cb39c2$0aa2a120$1fe7e360$@rr.com>
> Content-Type: text/plain; charset="us-ascii"
>
> At first it started with some whirling noises. Then it started grinding.
> Leaving work today  the car backed up about 4 feet and it felt like I hit
> something and stopped dead.  Talk about your "clunk". Tomorrow it'll come
> home on a flatbed.  I know this isn't going to be cheap.
>
>
>
> So, what are my options?
>
> 1. Get it repaired by a local TR repair shop, assuming they have the tools.
> How much is that?
>
> 2. Update (upgrade) to a Nissan differential ala Bob Danielson. How much is
> that?
>
> 3. Have the guys at TRF repair it. How much is that?
>
> 4. Go to a british junk yard and get somebody else's junk. How much is that?
>
> 5. Try to repair it myself. How much is that?
>
> 6. Other. How much is that?
>
>
>
> Recommendations? I've had the car since 1970 and would hate to part with it.
> The list above is in my order of preference, but bow to the wisdom of the
> experienced ones.
>
>
>
> Johnnie in beautiful San Diego
>
> '67 TR4A IRS
>
> '71 Volvo 1800E