JimSpencer
|
| posted on 3/10/14 at 10:12 AM |
|
|
Hi Raj
Good stuff - re the broken bits:-
See if the conical drive flange is seperate to the small shaft - it should be - unless it's been tag welded onto it
The small shaft (with the boss in the centre) has splines at both ends, so can be a very tight fit into those flanges.
It can then simply be got from MiniSport (or similar) - "Mini LSD Output shaft Pot Joint Type"
See you at a track sometime
|
|
|
|
|
dave_424
|
| posted on 3/10/14 at 10:17 AM |
|
|
Can you measure the OD of the splines that broke? I'm having the same issue with a diff converted to chain drive that has 25mm OD splines with a
portion just after the splines that is 22mm OD
Dave
|
|
|
minitici
|
| posted on 3/10/14 at 01:00 PM |
|
|
quote:
Originally posted by JimSpencer
Hi Raj
Good stuff - re the broken bits:-
See if the conical drive flange is seperate to the small shaft - it should be - unless it's been tag welded onto it
The small shaft (with the boss in the centre) has splines at both ends, so can be a very tight fit into those flanges.
It can then simply be got from MiniSport (or similar) - "Mini LSD Output shaft Pot Joint Type"
See you at a track sometime
Your Quaife differential is probably based on the Ford Fiesta/Escort and would normally use push-in CV joints.
Jim's Quaife chain drive was based on a Mini unit which has totally different output shafts.
The bolt-on flanges you have look like specials.
Quaife do make (expensive) 100mm OD lobro bolt-on output shafts to suit the QDF7ZR differential although they may be slightly different length to your
specials.
I have made several special output shafts with Lobro flanges (94mm, 100 & 108mm OD types) welded to stubs machined from Fiesta CV joints.
The Fiesta/Escort CV joints are 22 spline (about 25mm OD) the journal on the stub is about 28mm OD.
[Edited on 3/10/14 by minitici]
[Edited on 3/10/14 by minitici]
|
|
|
Autoflock Motorsport
|
| posted on 3/10/14 at 01:46 PM |
|
|
yes these are specials, like averything on this car (raj frowns)
im just redrawing these up now in cad so I can have more made once this is fitted.
Large spline dia - 27.8
Small spline dia (where it failed) - 25.4
these are just rough measurements quickly taken with my vernier so hope this helps.
Just had a puller made up to remove the input shafts easily.
Let me know what you think
Kind regards
Raj
http://www.locostbuilders.co.uk/forum/23/viewthread.php?tid=183445
|
|
|
Autoflock Motorsport
|
| posted on 6/10/14 at 09:13 AM |
|
|
well got tit all back together friday night and went to aintree saturday for a track day, did 6 laps and the same thing happened with the other side.
NOT IMPRESSED
Ive not removed it yet but im guessing it has sheared off in the same place as the other one, where the spline changes diameter. Anybody got any
advice or input on the cause of this??
Kind regards
Raj
http://www.locostbuilders.co.uk/forum/23/viewthread.php?tid=183445
|
|
|
minitici
|
| posted on 6/10/14 at 10:31 AM |
|
|
quote:
Originally posted by Autoflock Motorsport
well got tit all back together friday night and went to aintree saturday for a track day, did 6 laps and the same thing happened with the other side.
NOT IMPRESSED
Ive not removed it yet but im guessing it has sheared off in the same place as the other one, where the spline changes diameter. Anybody got any
advice or input on the cause of this??
Check what grade of steel and what heat treatment was used.
|
|
|
cloudy
|
| posted on 6/10/14 at 10:53 AM |
|
|
Sounds like the output adapters had a defect, as minitici says your particular diff is based on a fiesta, in which the shafts will receive much more
abuse!
James
www.warnercars.com
|
|
|
Autoflock Motorsport
|
| posted on 6/10/14 at 10:59 AM |
|
|
the steel we think is EN32 or 40b which has been tempered and case hardnened. I think its the shape of the splines which may be at fault, where it
changes diameter, not too sure which shafts have been used though.
Im not too sure why these input shafts have been made, its a pain in the arse not being able to buy them off the shelf. I have since produced cad
drawings to get more made but now the other one has broke I am now thinking to bin the whole setup and start again???
The diff it self also feels like there is slack in it, I can rotate one wheel when jaced up approx 1" either way before the opposite wheel had
any omvement, is this normal?
Kind regards
Raj
http://www.locostbuilders.co.uk/forum/23/viewthread.php?tid=183445
|
|
|
dave_424
|
| posted on 6/10/14 at 11:26 AM |
|
|
I'm also looking for a chain drive lsd with splines larger than 25mm. Haven't really found anything use able yet
|
|
|
Autoflock Motorsport
|
| posted on 6/10/14 at 12:27 PM |
|
|
just spoke to the lads at spire, very helpful people, although they run the radical diff they gave me some sound advice about what they run. Im going
to have a work with the machine shop about the current design and get another one made with no change in spline diameter. Also looking into the heat
treatment side of it as I think it may have had too much making it strong but also brittle. The shock loading of the gear changes and slack between
drivetrain components has just been too much for the metal but this is only my speculation.
Spire use the shaftec PJ8N input shaft with the lobo joint and have had no issues, myself and friends have had these shafts taking in excess of 350bhp
& 300ft lb of torque pulling a fully trimmed fiesta so the spline diameter would be more than up to the job, which is why I think its a design
issue not a power one.
Kind regards
Raj
http://www.locostbuilders.co.uk/forum/23/viewthread.php?tid=183445
|
|
|
minitici
|
| posted on 6/10/14 at 01:46 PM |
|
|
quote:
Originally posted by dave_424
I'm also looking for a chain drive lsd with splines larger than 25mm. Haven't really found anything use able yet
If you really need a differential with larger spline output shafts, I build chain drive differentials using Quaife MTX-75 ATB's.
These use the larger 28mm OD splined outputs (30mm stub) CV joints. These units are used on RTR's Mevabusa builds.
|
|
|
