3.08 Diff Centre

MBH222 · Post by **MBH222** » Thu Mar 09, 2006 5:05 pm

Hi All, Im a new member. Just got an FB Specail Station Wagan this week after parting with my beloved EH Specail Wagon.
The question I have is to those out there who have fitted a 3.08 centre to thier FB that still runs the 3 speed. I am considering changing the 3.55 down to the taller 3.08 so the grey motor doesnt rev to hard on the open road. Any thoughts? Would this be a good idea? Does 1st gear become too tall with the 3.08 centre.

FB MAD · Post by **FB MAD** » Thu Mar 09, 2006 11:58 pm

Hi MBH222.I've never ran anything other than the standard 3.89 grey motor diff but will be playing with ratios myself soon.From what others seem to be saying the 3.55 is a good diff to use if you don't want to lose too much power and it helps minimise the resultant speedo error due to diff ratio change when you are running modern smaller diameter radial tyres which are around 22 inches diameter (60 profile) as opposed to the original 24 inch diameter crossplys.

3.36 will give better economy but another step in pickup loss.From the experience of others this seems to be the limit in comfort that a standard grey will run OK with as they do have a bit of a struggle on bigger hills.A worked motor will cope better than a standard motor.

I think a grey will struggle with a 3.08 unless it's a worked motor although I haven't heard about anyone useing this ratio with a standard grey.

None of the above is from personal experience.It is only from reading the comments from others who have played with ratios and what they have found.

Hope this helps,

Terry.

earlyholdenfan · Post by **earlyholdenfan** » Fri Mar 10, 2006 7:42 am

Just as a little footnote on this, when I bought the wagon someone had fitted a 3.08 centre and along with the Hydramatic, it was shocking! it seemed to be alergic to any hill or rise even speedbumps gave the car goosebumps,but fantastic on highway trips!

, so much in fact that I changed back to 3.89. When I put the trimatic behind the grey I switched to 3.36, and as other that driven the car will testify, it works quite well, great off the mark and comfortable on the highway, so maybe look into this as an option as well.
Matt

MBH222 · Post by **MBH222** » Fri Mar 10, 2006 8:45 am

Thanks for your replies Terry and Matt,

Seems that the 3.36 may be the centre to change too. It just happens, that I have a spare diff out of a HR sedan that has a 3.36 centre. I may look into making the changes. Will evaluate the FBs performance this weekend that will be its first trip.

Currently my FB runs the original 13's. Do you of any companies that reproduce 14's-15's to fit the stud pattern for FB's, whilst still looking original. I know the HG,HT rims fit the stud pattern. Just a matter of finding them. :)

Michael

FB MAD · Post by **FB MAD** » Fri Mar 10, 2006 9:53 am

G'day Michael.Let us know how the 3.36 goes as thats the ratio I'm looking at with my standard grey in my EK Sedan.Is your grey motor standard or modified??
Referring to the original looking 14 inch rims.There was a post either on FE/FC Holden forum or Old Holden.com where a bloke had the number of a place that still sold brand new R.O.H 14 inch rims to suit early Holden stud pattern and from memory they were priced under $100 each.
Give me a few days and I'll see if I can find it and let you know here.
Volvo 15 inch rims fit but they don't look very original.

Terry.

Devilrod · Post by **Devilrod** » Fri Mar 10, 2006 12:41 pm

MBH222 wrote: I know the HG,HT rims fit the stud pattern. Just a matter of finding them.

Michael

Post a wanted add on the forum. I did that here and on another forum I frequent and ended up with 5 for free. Just had to pick them up....(and they were local)

MBH222 · Post by **MBH222** » Fri Mar 10, 2006 1:37 pm

Hi Terry, I did hear that ROH did the original rims, but thier web site was not very helpful and I was beginning to think they had seised production. I will check out the Forum and website you mentioned - thanks.
My grey motor is standard only has 59000 original miles on it so it goes like a dream.

I think it has some very very early electronic ignition as the old fella who was the orginal owner was a electrical engineer - apparently as his story goes he invented the system and then the larger car companies did not allow him to patent the design - HHmmmmm

Another idea i had was get custom 15' rims, cut the centres out and insert the original FB centres in but too costly at present. I have seen an FJ with this done - looks very good.

Devilrod - Monkey see monkey do. Ill post a wanted add. You did very well - 5 freebies

Devilrod · Post by **Devilrod** » Fri Mar 10, 2006 2:58 pm

MBH222 wrote:Another idea i had was get custom 15' rims, cut the centres out and insert the original FB centres in but too costly at present. I have seen an FJ with this done - looks very good.

Just on doing that I think from memroy you can go 14 - 15 on what is called a mexican rim (extra steps in the rim to get to 15) but I don't think you will get 13 - 15. I could be wrong as I haven't seen this done in a while.

EK-179 · Post by **EK-179** » Fri Mar 10, 2006 3:08 pm

Devilrod is right there, i believe that is how you can run 14" with original hubcaps, although i dont know what a very original fb wagon would look like with 15" rims on it. i would say 14's would be ok though, as for rims go to your local wheel/tyre place as im sure they will be able to get them in.

earlyholdenfan · Post by **earlyholdenfan** » Fri Mar 10, 2006 10:09 pm

ROH make them in 4.5 and 6 inch sizes with the early Holden stud Patern, as a replacement for the HKTG studs on trailers, I found out the hard way that the 4.5 inch (std width) rims do not have hubcap nibs, so you have to either weld a bead on or forget hubcaps, they generally will not like dress rims either, the 6 inch ones (I am told) have the hubcap nibs, and may be a better option, but you loose the origianlity of them, if you are in Melbourne I have a number for the dealer (he used to work at ROH) that supplies them from ROH as the wont sell directly to the public.
just as a guide the 4.5 inch rims are around the fifty bucks a rim, and you need to buy new wheelnuts, as the taper is different.
Matt