Diff's

[Bas / NZ]

Ok Guys, someone in the know out there. I have 2 standard BEDFORD  Diffs one is  the Square back one i thinks is 9" DRUMS and the round back diff I think is 10" drums.

Can I change over the 10" backing plates and drums etc to the square 9" diff or not?

(If not) does anyone in NZ have a set of 9" drums  (think I have the backing plates) for sale

And for the guys in NZ, where do I get a new  pinion oil seal.

Any help thanks Bas

[john]

yes you can change them over but!!!!! you need to change over the plates behind the axle bearings, 9inch have 4 bolts, 10 inch have 6 bolts and shaped differently, you need at least 20 ton press.

[Bas / NZ]

Ok, thanks for that John, on a closer look, (now that it is daylight  the plate behind the axle bearing is welded on on both these diffs. Cheers Bas

[Bas / NZ]

Ok to all you guys out there running these 3.8 v6 in your Bedfords, or those in the Know.

Do you need a 3.5 etc rear end in a bedford, yes I know the Car has this but the Bedford is a lot bigger, well my Jumbo is, and it is running the TH 700 4 speed overdrive.

With the standard 4.1 the advandage is you have a lot more power of the mark and the final drive is there a different ratio between the 4.1 and 3.5 once you are in 4th (overdrive)

I understand gas usage around town would be higher with the 4.1. but this is out weight by the power gain to me..... Ok it makes me feel like I have a V8

THE REASON I ASK THIS AS MOST WILL KNOW WE HAD THE 2.8 TURBO DELICA VAN, THAT I SHOWED PHOTO'S OF THAT A TRUCK DECIDED TO TAKE OUT. (SH...T CAPS ON)

This Delica ran a 4.1 rear end with overdive Auto from factory

Thoughts info please, I'm am leaning towards leaving the 4.1 in , as at the moment with the Duels, I think it is a 5.1 ratio.


Cheers guys. Bas

[Rogue Trooper]

Do you need a 3.5 etc rear end in a bedford, yes I know the Car has this but the Bedford is a lot bigger, well my Jumbo is, and it is running the TH 700 4 speed overdrive.

The VN I got my engine out of to my knowledge had a 3.08 ratio. The Jag I have put in has 3.07 ratio so I'm just going with that till I see how it performs. It should be fine around town but the van has that extra wind resistance factor when it gets to open road so that may be an issue. If it is I'll just swap up then.

Of course you're putting yours into a Jumbo so weight and wind resistance are probably more of a factor than my SWB (even with the metalwork  ) .

[wraithknight]

excuse my dumbness but just so i know how it work if say you are running a 3.08 diff wich way do you take it to gear it up for betta road speed

im no machanic aye can do most stuff like cams and rings ,bearings that sort of thing but gear ratios have know idea

im more your body kit modifier

[Rogue Trooper]

If you go to something like 4.1 or 5.1 that Baz is talking about you will get better speed off the mark but higher revs at the top end. If you are drag racing this is great but not so good for fuel economy at the top end. Much better for carrying heavy loads and things like campers.

Ratios like the 3.08 are much better for things like cruising at open road speeds as it keeps the engine revs down and thereby improves fuel economy but it is not so good taking off from standing still especially if towing a heavy load.

You can get the effect from riding your mountain bike. Pick a low gear and take off from standing still. It's quite easy but once you get up to speed you'll find your legs are going round quite fast at a given speed and you end up puffed. This would be a 4.1 ratio.

Now if you pick a higher gear and take off you'll find it harder initially but as you get up to the same speed as previous you'll find your legs don't have to go round quite as quick to maintain the same speed so you can breathe more easily. This would be a ratio like a 3.08.

[wraithknight]

ok get it now the higher the ratio the quicker the take off but the topend speed drops the lower the ratio the betta the top end but you loose your take off speed

[BusyKiwi]

You wouldn't want 4:1 behind the commodore. I started with the 3:08 but wasn't happy at 100kph (at 2300rpm) so went to 3:3 (i think it was), with a heap of stuff in the van it towed the custom van down to the nationals well (except the trans over heating at the end), even going up the bombays it only went into 2nd a few times, i did plant it once to see if it would jump into first and it did but it cruised nicely.

with the commodore centre you can go up to 3:7, you can get 3:9 and 4:1 but they are later model and larger and require some machining to fit.
Give the guys out at "diffs r us" a call, they worked out the rpm range of my new gears off the top of his head and was pretty close.
Your tyres also play a big part in it as commodores came out with 15" but a high profile (60 series) tyre can be similar size - I think it was 26 inches around the trye

[Bas / NZ]

Thanks Guys, David would love to put the round heavy duty bedford diff under her, but not sure about fitting the cresta or holden head into this, as Murry said it fits the round diff, but I have two of the square back plate diffes here with cresta in, ( I'M Lost)


Will be running 275 x 60 on 15x8" rims rear and 215 x 70 on 14x7" rims front

ANY ONE GOT SOME 9" DRUMS PLEASE PLEASE, WILL THEM BE ABLE TO GO WITH THE BEDFORD DIFF I HAVE HERE WITH THE GRESTA ALREADY IN IT..........

I thinkk this van is running 4.1 diif and v6 and 5 speed?