The Triumph Dolomite Club - Discussion Forum

Hi, I have stripped my 1300fwd gearbox down to make sure it is ok before refitting it, it is easier when its on a bench. Had two manuals at hand to make sure I did not make a mistake.
First thing that struck me was there was no RD number anywhere like the manual said, only cast-in numbers on outside of: 8840285, also DA21734 and 343 above the Stanpart emblem.
The transmission was really clean with no crud to clean off so maybe a refurbished one. There are no gaskets, just silicon sealed joints. The main difference is that I have bought a new input shaft and matching gear for a 1300fwd and it is nothing like what is on the current gearbox - see photo.
Dimensions for the current one are: Gear width: 23.30 Gear O/D: 53.20 Overall length: 77.30 Shaft spline length: 28.75
Dimensions for the new 1300fwd one are: Gear width: 18.50 Gear O/D: 48.40 Overall length: 71.35 Shaft spline length: 34.25

Obviously the new 1300fwd shaft and gear will not fit, so what is this gearbox - is it a 1500fwd one fitted to 1300cc engine?
Did notice on stripping that there was only 1 dowel locating engine block to transmission casting - is this because they do not line up as the 1300cc engine does not fit a 1500fwd transmission?
If it is a 1500fwd gearbox, what would be the effect on the 1300cc engine performance?
If it is a 1500fwd gearbox, can I still get a new input shaft and gear?

Thanks for any advice you can give.
Pete

The splines on the 1300fwd input shaft are prone to stripping. Steve W. had these remade in the 1990s to an improved design. The 1500fwd didn't have this problem because the input shaft is slightly different. The remade 1300fwd input shafts are now available from Canley Classics.

I did get the new set from Canley Classics so I presume they are to the new design.
Pete

Yes those are the ones. When reassembling, you will need the special grease. Alan Cassie (the 1300 spares man) can supply you with some if you don't have any.

But as the gear diameter is different, then I cannot fit them.
This makes me wonder if it is a 1500fwd box?
Can anyone advise if it is or not and whether gear and splined shaft are available for a 1500fwd?
Thanks for reply's Toledo Man

Hi Pete.

I've run a 1500fwd gearbox for many years in my 1300. It does give better gear ratios.

Yes the primary gear and input shaft are different and are not interchangeable.

Also the aluminium rear casing is different to the 1300 box needing a different rear mounting. I seem to remember yours being different, do you have any pictures ?

P.S

Just had another look at you photo's of the input shafts, the bottom one is a 1300 shaft not a 1500 one but the primary gear is 1500 !

Hello again, thanks for reply.
Have attached some photos and I think the casting is different to the pictures you sent some time ago.
Reference the picture of primary gears and input shafts I posted, the top set is the new ones I brought from Canley Classics, which I ordered as 1300fwd ones.
The bottom set came out of my stripped down gearbox.
I am really confused now with what you say!!!!
Certainly, the shafts are not interchangeable as the undercut for retaining ring is in a different place, although the splines dimensionally are the same and therefore do fit into each primary gear.
If the photos confirm it is a 1500fwd gearbox, then what should I do - buy a new primary gear and shaft for a 1500? If Canley Classics do not stock them, do you know who does?
The large ball bearing that the primary gear runs in does not sound too good now it is cleaned up. Do you know if it is common between 1300 and 1500 gearboxes?
Do you have a drawing of the 1500 gearbox mounting?
Sorry to ask all these questions, but I am really scratching around for info.
Many Thanks
Pete

Yes Pete that's a 1500 gearbox alright.

Sorry for the confusion with the input shafts. You appear to have been using a 1500 gearbox with a 1300 input shaft, the 1300 shaft is about 0.5" shorter than a 1500 one, so either you weren't getting full engagement on the primary gear splines or it wasn't going full into the spigot bush in the end of the crankshaft ?

I am a bit puzzled with how the gearbox was mounted at the rear as it looks like you have the remains of a 1300 mount on your subframe, the rest of which would not have mated with the 1500 box! Ironically the pictures Tinweevil posted on your resto' thread show the 1500 gearbox and subframe the latter showing the extra piece one the rear for the different mounting ( the 1500 subframe is a 1300 one with bits added to it )

Do you need to replace the primary gear you have? the uprated one for the 1300 is of the 1500 design, this upgrade Triumph did themselves when the 1500 was introduced. I believe Mick Dolphin has some 1500 primary gear bearings. you just need to find a 1500 input shaft.