Hewland HD5 gearboxes

[KWhittle]

I have just purchased HD5 serial No 94 from New Zealand.
Does anyone know its history. I understand 105 were constructed.
What age is No 94 ?
Does anyone have a HD5 manual ?

[Bryan Miller]

Kevin,

Suggest you get in touch with Peter Smith at PDS Racing on 01977 611928.

Peter is a fellow Hewland distributor and is the man for HD 5s.
I have been watching that advert for a few years wondering why the gearbox hadn't sold , possibly it came out of a Tasman Brabham or similar.

A lot of parts can be replaced with FT200 ,with a small amount of modification FT gears and crown wheel and pinion can be used , as the gear centres are very very close.

Bryan.

[PeterMorley]

Originally Posted by Bryan Miller

A lot of parts can be replaced with FT200 ,with a small amount of modification FT gears and crown wheel and pinion can be used , as the gear centres are very very close.

Alan Baillie has modified the HD5 in his Lotus 24 to take FT200 gears.
He could probably help you if you want to go that route (01189 722 541).

Finding enough usable HD5 ratios was a problem when I had one, plenty of land speed record gears but not enough lower speed ones. Modifying it to take FT200 gears makes ratio selection a lot easier - but there are apparently some drawbacks/difficulties with the modifications.

Given their similarity an FT200 manual might be close enough?

Apparently the weak point on an HD5 is where the main part of the casing joins the differential housing - the two parts can become seperated!

I did see a photo recently (possibly South African) of an HD5 that had what looked to be a reinforcing frame bolted to it - between the diffhousing (e.g. sideplate mounts) and rear of the box (e.g. bearing carrier) - presumably to alleviate the problem.

[KWhittle]

Thanks guys.
Bryan, the problem seemed to be that Russ Cunningham never replied to any enquiries. It took me a year to get a reply. Nice guy but too busy perhaps to reply.
Peter, My box came with a lot of ratios, but some duplicated. It seems to have been fitted with FT200 side plates at some stage.

I assume that its a ex Tasman box and wondered if anyone would know. Peter Smith has sent me a copy of the two page document that was the only info Hewland produced.
I must get a FT200 manual if it is that close a match.

[Bryan Miller]

One of the Alec Mildren 2.5 Brabham Climax cars suffered this very problem, there is a photo in an Australian Autosportsman magazine captioned '' rear end breakaway '' where the maincase had totally split just forward of the side plates leaving the gearbox back section seemingly only held on by the driveshafts.

I stand corrected , however I believe there was a MK 2 case to solve this problem.

Kevin , you can download the FT200/FGA/FGB/FGC manual from the website.

Bryan.

[PeterMorley]

Originally Posted by KWhittle

Thanks guys.

Peter, My box came with a lot of ratios, but some duplicated. It seems to have been fitted with FT200 side plates at some stage.

Ratios sound good as long as your engine is similar rev-range to the original car, problem I had was the box was for a V8 car (±10-11,000 rpm) and we had an FPF (±8,000 rpm)!!

Someone on the internet has been advertising some HD5 sideplates for ages. Check out the small ads on PDS racing - it will be somewhere like that.