The Triumph Dolomite Club - Discussion Forum

Would anyone know if the Dolomite 1850 auto prop is the same/fits a sprint auto?


Cheers

Will

I don't think they are the same (different part numbers and joints I think) - no idea if it'd fit or not.

Firstly, I need to state that I have not tried this myself but
if you search the web you will find examples of folk using changing 1850 props for Sprint or vice versa.

From this I gather that the sliding section of the propshaft will accommodate
the small diifference in distances between the auto 'box and diff flanges, but
the centre bearing mounting ring is not quite in the correct position for the brackets on the floor.
Apparently there is enough give in the centre mounting's rubber to force it into position but
I personally cannot accept that as a solution, given how short lived OE prop centre mounting rubbers are normally anyway.

If it was me I would modify or make the brackets to keep the centre mounting as unstressed as possible.
In fact, while I was at it, I also definitely would change the centre mounting for a Ford Transit one, for longevity.



Ian.

Cheers Ian, I might get one made as they seem to be scarce, also maybe a straight through prop minus the c.v. Altogether?

My man at Proptech in Hartlebury Worcs will adapt anything to fit anything in the way of propshafts, or make a new one from scratch.

He's just built me a completely new 1 piece bespoke prop for a Rover V8/LT77 powered Stag to my specs for less than £200.

His opinion, which we have sought, is NOT to go for a single piece prop on a Dolomite, making it long enough makes it unconscionably large in diameter, excessively heavy and makes the angles bigger as only 2 joints to share them instead of 3!

It pains me to tell you that, as I write this, he is modifying a Sprint auto prop to fit a Nissan turbo engined Dolomite for a friend of mine. I know its an auto prop because I sold it to him a couple of weeks ago. I'd had it for years with nobody having any interest in it at all, so in the end I let it go for pennies, to be modded. Isn't it always the way!

But to answer your initial question, you would need to shorten the rear section by around an inch and a half, because the Sprint diff is longer. Plus whatever needs doing at the front end, i'd have to do some measuring. I have a standard Sprint auto here so I can get you the measurements you need to match.

For myself, I am disinclined to use the 1850 or 1500 props that have the sliding joint at the front. (as in your picture) This AUTOMATICALLY puts more stress on the fragile centre bearing from axle plunge. For my own highly modified auto I used a 1500 auto prop from a very late car which has 3 u/js and a rear mounted sliding joint. The rear sliding joint took up the axle difference and I only needed to take 75mm out of the front section and it was done.

Steve

Hi Will, the answer to your question is yes it does fit, as that is what is on my Sprint. In 2013 I replaced the manual overdrive ‘box in my Mimosa Sprint with an 1850 auto ‘box and it’s propshaft. That worked fine but last year (and after some 17000km) I was offered a genuine BW65 type 17 auto box and prop from a Sprint so set about changing these over, given the 1850 ‘box was showing signs of wear.

That done, a roadtest showed up quite a lot of vibration. Removed the prop and took both the Sprint and 1850 ones in for an expert opinion. Both turned out to be in need of refurbishment but it was determined that parts for the Sprint one were not available, but replacing the UJs on the 1850 one (that I had been previously using) along with balancing was possible and recommended. That done it has been fitted and is working fine. In fact the Sprint auto ‘box and this prop are proving to be very smooth running indeed. Have added another 1500km since then and it is a joy to drive. I should add that my engine is in standard tune and additional power from a tuned engine may perhaps be too much for this arrangement.

So, in my experience the 1850 prop simply bolts straight in with no issues whatsoever. However, I would recommend ensuring the UJs are not worn and you’ve had the balance checked.

Geoff

Cheers Steve, I’ll be on the lookout for a late 1500 auto prop then!

Geoff , music to my ears, can’t beat tried and tested, I’ll also take the 1850 prop in for a freshen up and start reassembling this car!