Bare
|
| posted on 1/11/11 at 06:00 PM |
|
|
TR 7 axle??
Found a couple locally for reasonable, but not bargain prices...
55.5" mount faces makes it usable on a Cat SV 'Clone" chassis.. my intention.
Not put off (too much :-) by the thought of a live axle and rear drum brakes.. MY hero driver days are loong gone:-).
Has some appeal as it would 'match' my Triumph uprights/hubs/brakes and steering.
Still not enamoured with the Spitfire Non hubcentric wheel mounting setup. But at least with a TR7 axle the rears would be hub centric... less to
upgrade/mod
Any one have any insights on these axles?
Erm.. are they problematically heavy? Are they durable..likely to be pre broken?
As in what typically fails and what to look for when trying to examine a greasy rusty lump lying on the ground?
|
|
|
|
|
cs3tcr
|
| posted on 1/11/11 at 06:39 PM |
|
|
First off, which axle? The 4 speed or the 5 speed axle? The 4 speed is almost correct, as its very similar to the Marina/Ital axle. But, its weak.
There's a guy in town who's snapped countless axles with his Cat running a 1700 crossflow. If you have your heart set on it, look into
some heavy duty axles, and keep a bunch of spare diffs on the shelf.
If its a 5 speed, they are stronger but heavier. I would look at a Cortina axle before getting a 5 speed one. The conversion front hubs (to go to
the Ford 4 1/4" PCD) arent that pricey, but finding suitable wheels in Vancouver could be a problem.
|
|
|
britishtrident
|
| posted on 1/11/11 at 06:59 PM |
|
|
The late Tr7 and late Dolomite 1850 axle (and the rclosely elated Sd1 and Sherpa axles) is a very strong unit, it uses the MGB, Triumph
2000/Stag & Austin Maxi PCD of 4.5" this much larger than the smaller Triumph models which were 3.75" (or was it
3.875" ?)
The early Tr7 & early Dolomite aand all Marinas used a very weak Standard-Triumph axle the origins of which goes back to the Standard 8 &
10. The differential from this unit forms the basis for the Herald final drive assembly.
The hubs can be re-drilled to Ford/Rootes/Peugeot 4.25 pcd but but I am not sure if there is enough room to re-drill to the very small pcd used
on most Triumphs & the Marina.
Don't get hung on hub centric location it is no consequence if you have wheels drilled on the correct PCD.
[Edited on 1/11/11 by britishtrident]
|
|
|
Bare
|
| posted on 1/11/11 at 08:03 PM |
|
|
Great information Gentlemen.. yet again.
I have little to no knowledge of TR7's other than I found them ugly.
I was led to believe these were from 1980 Cars Would they not have all been 5 spds by then? Dunno, just asking :-)
Hub centric is of concern as I had an Europa (for 12 years.. sigh) and it was an ongoing issue with wheel centricity/balancing.. Swore then that I
would never willingly repeat that... just trying not to :-)
I have a lo miles Honda Integra erm.. 'son damaged' in my garage that has all manner of very nifty bits.
Sadly, Very few of which are easily useable on a 7. Least of all the motor which rotates in reverse to usual practice.
But hubs wheels brakes are as new and possibly(?) with some ingenious machining.. useable on the Triumph stub axles, front and rear.
This axle weakness is worrying and a 30 yr old one that's been lying about doesn't hold a lot of promise either.
|
|
|
britishtrident
|
| posted on 1/11/11 at 09:00 PM |
|
|
You Europa problems were most likely down to the taper of the wheel nuts being wrong for the wheel.
Hundred of millions of cars were built without hub centring and it never gave any problems the French even did it for years with only 3 wheel
studs/bolts, in contrast hub centring has with stuck wheels and is theoretically bad because it over locates the wheel ie you get a potential
conflict between the centring of the hub and the nuts.
|
|
|
Bare
|
| posted on 2/11/11 at 02:08 AM |
|
|
Well that's One man's opinion... possibly even true :-) I only Bought the thing .. Lucky Me Although I've NEVER had any issue
whatsoever with wheels/balance since buying cars with hubcentric wheels.. Are there even anything else available .. these days ??
Had an R8 Gordini, so some familiarity with 3 bolt wheels.. they worked well.
Could also very well be (likely) that my hapless Europa, like my previous S3.. 7 was built by complete numpties, from substandard components.
Given all the mechanical atrocities found on Both cars, it was very likely.
Children could have done better work.
Lotus, IMO were clever designs, absolutely ruined by abysmal execution.
Apparently the tradition continues, by anecdotal evidence from colleagues who have bought current product.
Happily no current lotus product appeals in any way.
Regardless, simply NOT willing to endure it again... just not worth the candle.
The current question remains:
How does one differentiate betwixt a 4 spd TR7 rear axle and a 5 spd version.. by peering at it ?
[Edited on 2/11/11 by Bare]
|
|
|
cs3tcr
|
| posted on 2/11/11 at 03:22 AM |
|
|
The 5 speed has a cover on the rear of the axle housing to acess the guts. The 4 speed looks like an English axle or any other axle with the diff
removable as a unit from the front of the axle casing. If you google rimmer brothers, or even moss you should be able to find a good diagram of the
two axles.
|
|
|
Bare
|
| posted on 2/11/11 at 05:05 PM |
|
|
Thank you... for that.
Just discovered that the axle available IS a 1977 4 speed one.. Sighh.
erm.. Just how 'weak' is it?
IF it's equal to the earlier Caterham fitted Morris Marina units? then I'm thinking it's adequate to my needs.
Only planning on 100/ 110 hp.
Again, as a recent retiree... there's not much that would make me 'attractive to Wimmin'.. so not bothering to try :-)
Could always find/use a 740 Volvo axle. Without doubt, strong enough but seriously heavy.
|
|
|
cs3tcr
|
| posted on 2/11/11 at 05:11 PM |
|
|
The 4 speed axle should work just fine for that kind of power. Any idea the torque you want to transmit through it? Also, what tires are you
planning on running, sticky wide ones etc? Like i stated, you can get HD axles from various SCCA suppliers, though the diff is then the next part to
fail.
|
|
|
Bare
|
| posted on 2/11/11 at 05:49 PM |
|
|
Just perused Rimmer bros Lots of info there.. had never seen it before, thanks for the head's up.
Planning for a light-ish 1600cc 4cyl engine with decent revs and average torque (no turbos) and era appropriate rubber. Likely 13/14" rims..
maybe? up to 6' wide with 195's..as the max envisioned size though.
Goal is to keep it light as reasonably possible.
Not intended as any type of race car... just a sunny day toy and an 'adventure' to build.
Will have to go examine the axle for actual condition.. then decide.
Considering a plan B backup 'just in case' using a BMW diff/ axle setup.
Those are easy to get a hold of and can be of recent vintage at least.
[Edited on 2/11/11 by Bare]
|
|
|
