Dolomite Sprint Differential install in an Marina SWB

[stevejgreen]

There have been a few scattered posts on Dolomite sprint differentials, but I am hoping to consolidate the info.
I have just bought one. I think I know what I need to do to do with it.
I am looking at
A stud swap on the front hubs to 7/16" (old ford) so that I have the same all round, my alloy wheels should be OK
I have new spring hanger saddles to fit as nothing on the sprint axle matches (rallydesign part RD544 or make your own)
An obvious stripdown and rebuild of bearings seals braking system will be needed.

I have two questions.
On an SWB is more space needed for the nose of the diff?
What handbrake arrangement have people used as it differs from standard Marina?

Hopefully I will manage to get some photos as I go along but will probably put them on the MMOC forum as picture posting is so much easyer.

[CosworthCabrioLee]

Re: Dolomite Sprint Differential install in an Marina SWB

I have used the Dolomite sprint axle in my lwb Lotus powered roadster as it is the same size pcd etc. However the nose is much larger and you need to cut a part of the large webs away from the nose to clear the tunner and may need to change the tunnel and this can be a problem on a swb.One area you may need to look at is installing a panard rod and anti tramp bars as to stop axle movement side to side. the diff flange needs reduced as it is much larger than the Marina flange and you will need a smaller propshaft. Regarding the brakes when I first installed the axle I used the 10" drums and they where very good perhaps too good, now I have upgraded to Discs using Vw calipers and Citoren discs and Vw handbrake cables.

[stevejgreen]

Re: Dolomite Sprint Differential install in an Marina SWB

Thanks for that Lee will ask some more questions later.

If it all gets a bit fraught modifying the tub, there may be a fully modded, rebuilt axle appearing on ebay.

Yesterday was one of those days when I was full of enthusiasm. Out with the anglegrider in the open air with the Ashes coverage on in the foreground. Given a cold beer it would have been perfect but weilding an anglegrinder then would have been a bit dangerous.

Has anyone got any ideas on Handbrakes please?

[daniels917]

Re: Dolomite Sprint Differential install in an Marina SWB

Hi Steve i did this conversion on my swb last year, cut the large webs away, the prop flange fitted without mods, and i grafted the marina handbrake cable system straight on, i am running a 2.0 pinto at about 150hp, and this axle is great only difficaulty was getting the spring seat angles correct so that the prop runs true.

[stevejgreen]

Re: Dolomite Sprint Differential install in an Marina SWB

To both Lee and Merv, and anyone else.
If you have photos of the install and mods to the diff nose or build stages that you could email it would be a help.
Is this a Pitstop article brewing?

[email protected]

[stevejgreen]

Re: Dolomite Sprint Differential install in an Marina SWB

Does nobody else have any more ideas suggestions or experiences on fitting a sprint axle.
I would have thought it would have sparked more interest, with the possibilities of modified rear suspension etc etc.

[lil_red_roadster]

Re: Dolomite Sprint Differential install in an Marina SWB

OK...you asked for it...!

5-link setup...optimum length for radius arm is 8-12"...so using the forward spring mount is out...and the body side is a bit flimsy...but, an upside-down tower welded onto the chassis rail and braced back to the spring mount would provide a good basis for attaching parallel arms.

For coilovers these could be hung off a new cross-member welded in front of the existing lateral x-member (which carries the upper shock mounts)...OR just have single long arms running from the front spring hanger and angled top arms going to a x-member across the front of the rear bulkhead...(very close to the original Dolly setup). Some fabricated axle brackets (Escort Grp 4 - Rally Design), a Panhard or Watts link and jobs a good un.

Or just go the whole hog and fit a Locost De Dion axle and Sierra diff...or (and now the wine really is flowing) forget the Sierra and use a Triumph 2000/2500 diff, which is exactly the same as the big lumpy bit in middle of the Dolly axle but without the tubes...

Yours through the bottom of a glass darkly...

Jez

[stevejgreen]

Re: Dolomite Sprint Differential install in an Marina SWB

The axle is in and running, at least for a quick shakedown run.
All seems fine but I will check over and tighten it all up.

Most of the story is on the Marina Owners forum where more interest seems to have been given to the project than here. I will be updating the posts there in the near future if others want to follow.