Talk Morgan Forums Community For Sale & Wanted Wanted - pinion wheels for 1974 4/4

Hello

I have just acquired and driven down 850km through France a 1974 4/4 four seater. It's a cracking car with of course the 1600GT crossflow engine and the very slick 4 speed gearbox.

IMHO it does though cry out for a higher final ratio even for it's mainly non-motorway use, but I don't want to go five speed gearbox preferring to raise the ratio of the back axle (currently 4.1:1)

Does anyone have a good set of pinion wheels with a ratio of 3.7:1 that would suit the Salisbury 3HA axle lurking in their garage?

Cheers

I think that you should find that you have a Salisbury 7HA axle in your 1974 4/4.

Hello David

Thanks for your reply. Not sure where I read 3HA, but it certainly wasn't on the back axle itself so if you say it's a 7HA I'm happy to believe that. Will that make search for parts any easier do you think?

Cheers

I know someone who owned a 4/4 4 seater that had a 3HA, but it was fitted when the 7HA it came with broke. I think the 3HA is an older +4 axle, this car will have had a 7HA from new.

The daft final drive ratio was fairly typical at the time, you could get a 4.56 one too if you wanted up to the early 70s (not sure when it ceased to be available).

I did run out of revs in top gear at an airfield sprint once, gives one bragging rights I guess to say you hit the rev limiter in top gear.

Hi Philip, Billy Bellinger at JB Engineering hould be able to assist you although it may be easier to obtain a complete crown-wheel and pinion differential assembly and get it fitted locally.

Beware, to remove the differential assembly from the axle, one needs to spread the diff. case as the diff. assembly is larger than the hole and there is a special tool although it's nothing exotic.

Changing to a five speed gearbox won't alter the engine revs to speed ratio unless it is an overdrive gearbox. Most Ford boxes retain the same 1-1 ratio so will merely give you more gears to play with and not give you a higher ratio.

Personally, I'd have a chat with Billy Bellinger first.