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Posted: Wed Mar 26, 2008 10:25 pm
by oldgmh
I have a 2.78 coarse spline diff centre in my EK with a 202 trimatic and 13" wheels. The diff was from a torana. Twas cheap too - $110. :shock:

It is an excellent ratio for easy highway cruising at 110kmh and yet is still very good around town - as it should be as it is the same driveline combination that was from the factory in 202 engined auto toranas, which also had 13" wheels and weighed about the same as an EK. :D

Posted: Wed Mar 26, 2008 11:01 pm
by FB MAD
Can't give you Timken part numbers but can give you GMH part numbers if that helps.

From Master parts catalogue:-

Seal "O" ring rear axle oil FB,EK 7415353

Bearing assembly, axle shaft , bearing package x 2 ( probably includes oil seal ) FB,EK,EJ,EH,HD 7406719

Terry.

Posted: Thu Mar 27, 2008 10:53 am
by rosco
Thanks OldGMH - memory bank updated...............

frats,
Rosco

Posted: Fri Apr 11, 2008 6:45 pm
by strogger
thanks guys, job was a peice of cake..

Even an idiot like me had it done in under 4 hours, Includes rooting around replacing seals and cleaning up the shed.

Car was off the road overnight only :D :D

Posted: Fri Apr 11, 2008 9:01 pm
by rosco
Thanks Strogger - what did you put in and how do you feel it compares to what you had - for the information of those intending.....................

frats,
Rosco

Posted: Sat Apr 12, 2008 7:43 am
by strogger
In was a rebuilt 3.36 diff center.
Out was a 3.55 diff center, noisy and harsh due to bearings lost hard facing on cups and needles. Gears, crownwheel and pinion appear to be good condition to my surprise.

Car would scream, shake and shudder at any speed above 55 mph.
(So much that my ipod on 3/4 volume was barely audiable.).

the 3.36 has made the car a fantastic highway crusier, the grey seems almost lazy at 55 - 60 Mph, I am pedaling a bit harder around undulating terrain at lower speed. (Need to shift the hydra back to 2nd as i lose momentum)

My grey is an unkown offering, but feels and sounds to be in good condition, wouldnt suggest a 3.36 if your grey was tired or if you didnt do a lot of highway miles or wanted something to leap off the line at a traffic light grand prix.

A hot grey, auto, decent size rims / tyres and a 3.36 would be a sweet crusier for highway or town in my opinion.

Posted: Fri May 23, 2008 11:08 pm
by fb cruisin
Strogger your EK's an auto isn't it?
because I was wondering what ratio I should run behind my FB with grey motor and 3 speed manual,355 or 336 ratio.
I have 185, 70 series tyres and I'm finding with the standard ratio it is reving high.

cheers Rob

Posted: Sat May 24, 2008 11:17 am
by FB MAD
I'm running a 149 red in my FB and just ftted a 3.08 diff with 13 inch wheels and I'm very happy with the rev reduction at highway speeds.There is still plenty of pulling power on hills as well.

Depends on what sort of driving you do.Some blokes go 3.55 because they mainly do city driving,others go 3.36 to give some good highway driving.

With the grey being a bit down on power compared to the 149, I'd go with a 3.36 if it was my car.Then, if you weren't happy with it try the 3.55.It has been mentioned somewhere of someone going to 3.08 with a grey and they were happy with it because they did mainly highway driving but I still reckon 3.36 is a good ratio for a grey and the smaller diameter radial tyres that are being sold today.

My thoughts,

Terry.

Posted: Sat May 24, 2008 11:49 am
by strogger
Fb cruisin,
Yes mate, mine is an Auto.
As Fb mad said depends on what type of driving you mostly do.

But I really like the 3.36 in my auto. from memory the gear ratios are pretty similar between the manual and auto so would reckon a 3.36 would be ok in either.

Be aware a diff center rebuild can be costly, so make sure you get a good one if possiable.

Regards;
A.

Posted: Mon May 26, 2008 4:10 pm
by fb cruisin
thanks guys,
I have a 3.36 ratio thats been sitting in the shed for the last 3 years, I'm gonna get a bearing kit fitted and try that .

cheers Rob

Posted: Mon May 26, 2008 8:06 pm
by reidy
I tried a 3.36 in the "Rat" and took it to the Nowra Nationals. It was a great combination running 185/80x13's with a grey. I then switched to a 3.55 as i was towing a caravan. Still get good milage, cruise and off the line with this diff. Speedo is spot on as well.
Bill 8)

Re: Holden Diff Ratios

Posted: Mon Mar 05, 2012 3:35 pm
by Eeek
After all this Im still wondering how a 3.08 would go with the standard 138 and manual trans???? Or would you all recommend the 3.36?

Re: Holden Diff Ratios

Posted: Mon Mar 05, 2012 3:55 pm
by Trev
3.36 is as far as I would go.

Re: Holden Diff Ratios

Posted: Mon Mar 05, 2012 4:15 pm
by Eeek
Thanks, I got the wagon original but want to rat the sedan and give it longer legs so I might give that a try. Cheers 8)

Re: Holden Diff Ratios

Posted: Thu Sep 02, 2021 12:04 pm
by FbSTDwagon
Good info on the diffs here guys, thanks for that!

Question - is there is visual market on the diff centreswgich identified the ratios?

Or is it game of counting teeth?