Only 2 ratios were used on the 1500 models, manual, manual with overdrive or auto all the same. Early cars used a 3.89 ratio and later cars approx late 78 onwards used the 3.63 from the manual 1850. I can't remember the ID codes off the top of my head, no doubt someone will be along with them presently!
Thanks for that Steve.
I have been offered a rear axle, complete with brakes, from a Triumph 1500 TC Automatic, for the princely sum of £25, so I wanted to check whether it might be appropriate to my 1974 Triumph Toledo 1300 "HL Special", on which I wanted to change the effective gearing by about 5%, either by fitting larger circumference tyres or substituting a different final-drive ratio.
The vendor lives in Maldon, Essex, which is not too far from Canvey Island, Essex, for my friend and I to go and collect it in his car. The vendor also has an extremely-rusty late-model 1979/80 Triumph Dolomite 1500 HL Automatic which is about to be cut up, so I am hoping to salvage a few parts from that, with which to further upgrade my Toledo. Sadly, there are few parts they don't have, including a front bumper with mounting brackets and fuel-gauge sender with integral warning-light switch.
Looking in my two Triumph Toledo manuals and the official BLMC Triumph manual (brown-plastic, loose-leaf, four-ring file) for the 1973 Triumph Dolomite 1850, they seem to differ in wheel-track measurements, so I am wondering if there is any difference in rear-axle width and/or whether wheels of different offset were used!?!
Your original Toledo diff is of course a 4.11, i'll let you work out the percentages!
The 1500TC auto diff (if original) will be a 3.89 and the 1500HL will be (again if original) a 3.63.
I don't have all the wheel track data to hand, but I do know that you can put the diff and shafts from a 1500 into a Toledo case, 1500 and 1850 axle parts are similarly interchangeable,so my guess is the explanation for the track difference is down to wheel size (width) as the Toledo has narrower wheels from the factory than either the 1500 or 1850.
On another subject, with 2 autos breaking, your man may be able to help another member here who is desperate for a 21 tooth speedo driven gear for an auto 1850!
You can still get the 3 pin tank senders new from Fitchetts in Telford and probably other sources too. The bumper is a little more problematic! I have a late HL one here which is not TOO badly bent that it couldn't be tidied up and used, has irons and a semi respectable pair of underriders too. It's not rusty, just has a small kink at the nearside end and a scuff on the O/S corner. Will be cheap, but a bit big to post!