27 replies to this topic

[MFM]

Firstly I would like to thank forums members for responding to all my silly questions relating to my LJ XU1 which I purchased 12 months ago especially Bazza. I finally got it registered a week ago so before that,  the car hasn't been driven in 20 years (shed find). I'm now wanting to period correct a few things starting with the diff centre as I bought this car off a mate and we used to swap centres in the early 80's so not sure what I have in it but its feels tired so want to replace/recondition it with a period correct everything (centre housing/gears etc). I have 2 spare LSD centres and several spare crown wheels (308 & 2.78) that came with car. To start with centre housing what numbers do I need. Car is May 72. The spares housings I have, are dated "M 82" (3:55 LSD)and "27H4"(3:55 - LSD). The one currently in the car is "D221"(LSD) but has 2 long boss bolts which the other don't have?. The centre 27H4 LSD appears to be the tightest one. Thanks in advance.

 

[crabba67]

A diff centre out of a 5/72 Adelaide built body 42#A D282 LSD which i wrecked out 30 years ago i believe yours is in the 43#A numbers Cheers 

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[S pack]

 Car is May 72. The spares housings I have, are dated "M 82" (3:55 LSD)and "27H4"(3:55 - LSD). The one currently in the car is "D221"(LSD) but has 2 long boss bolts which the other don't have?. The centre 27H4 LSD appears to be the tightest one. Thanks in advance.

Mark. 3.08 & 2.78 diffs have the two long bolts. 3.55 & 3.36 diffs don't.

Edited by S pack, 13 February 2019 - 04:28 PM.

[MFM]

Ok so to get this clear, if the XU1 came with a 308/278 then it would have the long bolts from factory but if it came from the factory with 336 then short bolts. Some forum I read said that 3:55's were not standard in the LJ XU1's only 336? WTF, so what does that mean? I guess I'm trying to establish what housing (diff centres)came out specifically for the LJ Torana? or was it the case that whatever diff centre (long bolt or short) didn't matter as they were all the same from EH onwards (date depending). I'm trying to get the diff centre period correct. Paid shitloads for this car so I guess I'm trying to keep everything "period". Everything with this car is matching (original engine/box etc etc tags never been off etc) so yes I guess I'm what is referred to as a rivet counter .

[S pack]

Ok so to get this clear, if the XU1 came with a 308/278 then it would have the long bolts from factory but if it came from the factory with 336 then short bolts. Some forum I read said that 3:55's were not standard in the LJ XU1's only 336? WTF, so what does that mean? I guess I'm trying to establish what housing (diff centres)came out specifically for the LJ Torana? or was it the case that whatever diff centre (long bolt or short) didn't matter as they were all the same from EH onwards (date depending). I'm trying to get the diff centre period correct. Paid shitloads for this car so I guess I'm trying to keep everything "period". Everything with this car is matching (original engine/box etc etc tags never been off etc) so yes I guess I'm what is referred to as a rivet counter .

The majority of LJ XU1's left the assembly plants with the 3.36:1 ratio LSD. The two ratios that were available were 3.36:1 std and 3.08:1 optional, until homologation 5/5V introduced the 3.55:1 ratio in August 1972.

The only production XU1's fitted with 3.55:1 ratio diffs would have been approx 100 cars built in August/September 1972.

Your XU1 left the VAP with a 3.36:1 ratio LSD and banjo axle housing to suit. If your car currently has a 3.08:1 diff then either your axle housing has been swapped out with a 3.08/2.78 compatible housing or it has been modified by removing 1 threaded stud and welding in a nut to accept the 2nd long bolt.

[Bazza]

Hi Mark

 

The BETSBAC entry for you car indicates a 3.36:1 LSD.

 

Cheers

 

Bazza

[MFM]

Ok I know my diff housing is original as has baffles and stenciling letters, but diff centre is the questionable part. I might have to source out a period centre and get one set up in 336. Bazza what the hell is BETSBAC?

[meanmachine72]

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[grumpy xu1]

Hi Mark, it's the name of the gmh vehicle record system basically. Your diff centre or carrier (not housing) should roughly be dated somewhere around 4 to 6 weeks prior to the build date of your car in the casting number. You will be able to use the lsd hemisphere from either a 3,36:1 3,55:1 or 3,9:1 in your 3:36:1 centre when you have it rebuilt. Gary.

Good work Johnno. Gary.

[Bazza]

Ok I know my diff housing is original as has baffles and stenciling letters, but diff centre is the questionable part. I might have to source out a period centre and get one set up in 336. Bazza what the hell is BETSBAC?

 

A picture is worth 10,000 words.

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[dattoman]

A previous thread is worth something too right ?

 

http://www.gmh-toran...ousing-numbers/

[MFM]

Ok thanks for the replies. On another concerning note. Whilst I was under my car with the rear jacked up (on stands)looking at the cast number on the centre I was turning the tailshaft with one hand effectively turning both rear wheels and I can feel a grumbling type feeling through the tailshaft.Sort of like a bearing shell is stuffed and the bearing is rumbling over it. Also notice at around 60mph when I back off there's a vibration coming from rear with bearing noise which feels like diff (as I said earlier it feels tired). The feeling is the same whether I grab the front or the rear of the tailshaft. Want to fully reco the diff centre anyway so don't care if its diff, just as long as its not gearbox cause can't get parts for XU1 M20's easily these days. Any idea's

[RallyRed]

....""at around 60mph when I back off there's a vibration coming from rear""

 

I had that back in the day, it was a dodgy uni joint, just sayin.

[claysummers]

Ditto my 186 column manual HK wagon c 1979. Just over 60 mph. Probably 3.55 banjo. Replaced the unis all good.


Sent from my iPad using Tapatalk

[S pack]

http://www.gmh-toran...ossible-causes/

[MFM]

Thats a good idea to drop the prop shaft and feel the diff or at least look at the uni. process of elimination I guess.Thanks

[grumpy xu1]

It could be the uni's which you'd replace anyway, I'd like to think. But those diff bearings haven't really moved ect, for many years. You can buy better quality uni's like Hardie Spicer ect, but quite often they're an order in item.

[MFM]

I rang Diff Lapping in Brisbane this arvo. They've been around for 30 years anyway I spoke to them about my car and wanting to keep everything original and was mabey looking at a centre that had a casting day before May 72 (see previous comment from Anthony) so asked him if he had any lying around he could check the casting date on. He reckons they are rare to find these days. Bloody hell they were a dime a dozen in the 80's.

 

Can someone tell me what date code the diff centre I have that shows "M 82" there's a blank space between the M and the 8 for some reason?

[Bazza]

December 8th 1972. The space is there because there is no requirement for a 1 or a 2 to be placed there.

[I'm a Red Motor fiend]

If your going to drop the tailshaft, lever the uni with a screwdriver first to check for movement.

[meanmachine72]

find the right cast date housing and then put truetrac 28 spline in it, wont know its in there and its a cheap upgrade, $1200 for the truetrac $870 for 28 spline axles,

just done this to my 5/72 xu-1, i did have a 3.55 LSD bango centre that had cast date H 17 2, found this little gem in a gtr i wrecked

Edited by meanmachine72, 15 February 2019 - 08:55 AM.

[grumpy xu1]

Jonno, you're referring to the "centre" or "carrier". The housing has the axle tubes & "houses" the axles, just to avoid any confusion mate. Gary

[meanmachine72]

well iam confused now gary..lol

the diff centre has a housing and it houses the carrier

anyway you run whatever gears you want

 

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[grumpy xu1]

Sorry mate, i meant to say the housing is the big main bit & the bit that contains the gears is either the centre or the carrier. Just so everyone can understand, which part anyone else, is referring to. No chance of any confusion then. Gary.