fbekholden.com

Probably had this before , but what were the ratios used in them all , starting with the greys , anyone ?

Common Holden diff ratios are 2.78:1, 3.08:1, 3.36:1, 3.55:1, 3.89:1, 4.11:1, 4.56:1

Most common being 3.36:1 and 3.55:1 in the early models.

Regards, Smooth

ya missed one smooth 3.9 to 1 out of toranas
of all the others you mention smooth the front loading type are only 3.89,3.55,3.36,3.08,2.78? you can't get the others in front load can you?

OK , but so what would the different models / engine sizes have had ( not Borg Warner ) like what would the earlys had like my car, was HR whenithey changed , ?

All the early grey motor Holdens ( FX to EJ)had 3.89 diffs.You then got a choice starting in the EH Red motor of 3.55 or 3.36 depending on whether it was a 149 red or a 179 red but either ratio was an option if ordered.
Generally 149's had 3.55 and 179's had 3.36.

Somewhere around the HK Holden (or thereabouts) they started offering the 3.08 ratio behind larger capacity reds but was also probably an option behind other sized motors.

A 2.78 was offered in the LC/LJ Toranas behind the auto trans and may also have been an option in manual and also in the bigger Holdens as well.
Smaller capacity LC/LJ Toranas ie:- 2250 cc, 138 cubic inch red motor ( yes they did make a 138 red motor contrary to what some people think- I have one here at home to prove it! )....................................

Where was I??

Oh yeah, smaller capacity red's also had a 3.89 in the LC/LJ Toranas.

So there it is.

Red motor diff centres ( 6 cyl) can be fitted straight into the grey diff housing..... just have to change the grey motor rear universal joint to a red motor universal joint ( easy to do ) and then you have a choice of ratios to use from 2.78 up to 3.89 in the banjo diffs.

Terry.

Thanks for all that , you can have the day off tomorrow , but just one more thing is there a number on the housing somewhere as what it is ?
I had a near new LC GTR torana and in the owners handbook with the engine sizes specs. there was a130 CU.IN listed, but it only came with 3 Spd Floor shift , it said ! Never saw one , probably never was...

The 130 cubic inch red motor was an export only engine that would have been for the South Africa/ Asian exports only.
I've never known of one here in Australia but anything is possible I suppose.

If you have a red motor diff and want to know its ratio in most cases the ratio is stamped on the diff pinion oil slinger near where the yoke is. Just crawl under the car with a torch,screwdriver and wet/dry rag and scrape off the gunk.

Otherwise it will be stampd on the crownwheel but you need to pull the diff out to see the number on the crownwheel.
There is another way of telling the ratio by turning and counting the number of tailshaft turns required to turn the rear wheels once.
For example..... in a 2.78 diff the tailshaft will turn 2.78 times for every 1 turn of the rear wheels.

Hope this helps,

Terry.

GO THE MIGHTY GREY

hey Terry.


You state that all " grey motored" Holden diffs where the same ratio?? 3.89
I thought that the diffs in the EK hydraumatics where a different ( higher?? ) ratio to the manual ???

Son has a 149 EH wagon and wants to gear it up a bit for better highway croozn economy. Was hoping to use the EK auto diff but from what you are saying it would be worse going from 3.55 ( 149 ) to 3.89:1 ( all greys)

yes/no

The Ek diff is living in a sugar bag down the back shed. maybe it had been swapped from a later model car at some stage of its life. will check out the crown wheel tonight for some Number ID.

Reddo

Hi Guys.

The 3.89 ratio (FX to EJ) and the later 3.90 ratio are a different tooth count.

So the full list of banjo ratios is 2.78, 3.08, 3.36, 3.55, 3.89 & 3.90. To my knowledge there are no 4.11 or 4.56 banjos.

Dr Terry.

G'day Reddo,

Just consulted my GMH Master Parts Book and it doesn't give any separate listing for a different ratio for EK Hydramatic. It gives some different part numbers for some parts of the diff assembly in FX/FJ and also some other different numbers in FE/FC but they would be because of design changes not ratio changes.
So as far as I know all Grey Holdens were 3.89 including EK Hydramatic.
If anyone will know the answer it will be DR Terry (no not me... I'd only be the attending Nurse ) so maybe he could confirm?

If you used your EK Auto diff ( 3.89 )in EH housing you would have to change back to Grey motor rear uni joint and yep, you'd be going the wrong ratio way if you want economy.
If you currently run 3.55, try 3.36 or maybe even 3.08.
Don't know how a 149 would go with 3.08...... maybe someone on this forum runs same combination that can let you know??

PM me the crownwheel number Reddo and I'll look it up in the parts cattledog.

Terry.

P.S.
The 3.08 and ( I think) 2.78 can also be found with what most people call a "long bolt" centre.So if you have one of these centres you will have to get the "long bolt" ( its actually a stud ) and press fit (read... hammer and brass drift ) this stud into your housing. I have a long bolt 3.08 in a HQ here at home and made up my own "long bolt" to fit. Not a "press fit" and had to use a couple of copper washers but it worked well and doesn't leak.

Have just won a 3.36 diff center off evil bay...

I saw a previous post where:

Red motor diff centres ( 6 cyl) can be fitted straight into the grey diff housing..... just have to change the grey motor rear universal joint to a red motor universal joint ( easy to do ) and then you have a choice of ratios to use from 2.78 up to 3.89 in the banjo diffs.

Do i need to modify the tail shaft to accept the new uni joint / change
u-bolts ?

I want to have everything ready as i will need to pull daily driver off the road to change center and dont want to get half way through and find i hit a snag..

Thanks. Anthony..

Nup, no major modification needed.

All you have to do is buy a red motor uni joint, knock out the old grey motor rear uni joint and fit the new red motor uni joint to the tailshaft.You then only need to use the red motor 6 cyl uni joint U bolts and nuts to fit the new tailshaft rear uni to the replacement red motor diff pinion flange.

3.36 will bolt straight in to the grey motor housing providing its a course spline centre ( fine spline diff centres won't fit the grey's axles) and the standard grey axles will slip into the 3.36 diff.

Fill 'er up will diff oil and away ya go.3.36 should drop your revs around 500 rpm or so at around 60 mph compared with the 3.89 grey motor diff.

Terry.

Well my center has been given the once over and several hundred dollars latter the diff that was advertised (ebay) as being in good condition is now really in good condition.

So i am in need of some help; Can anyone tell me the axle bearing and outer axle seal part numbers for the rear axle ??? I want to replace when i fit new center but dont fancy pulling apart to identify and then reassemble to drive to pick up required parts...

After a Timken / FAG part number or dimensions if possiable ... I have access to seals and bearings of all types through work at a huge discount.
(No not theft , a massive trade discount. )


Thanks, Anthony.

Agree with all the above and very happy to read someone (Terry I think) made mention of the different axle splines - early are coarse - latter are fine.

If you intend to fit a 3:08 to a banjo, get the coarse spline - have no experience with fine spline but know the 3:08 comes in both - beware!
I don't think the 2:78 comes in a coarse................

frats,
Rosco