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Smallest Diameter CV joint.
DANMAN - 2/10/25 at 12:55 PM

Hi guys,

I’m chasing a really small diameter CV joint for my BEC front propshaft but due to the location of the output flange I am limited to an outside diameter of about 80mm.
Has anyone come across something this compact before?

This is the sort of thing I’m after but most appear to be 94mm OD.

https://ellerymotorsport.com/cdn/shop/files/LobroCVjoint-1.jpg?v=1698795639

HowardB - 2/10/25 at 01:08 PM

what about a CV joint from an ATV - quad bike thing?

adithorp - 2/10/25 at 06:06 PM

Why use CV joints on a propshaft, when a normal UJ at each end is a lot more compact?

DANMAN - 3/10/25 at 12:58 PM

I’m currently running uni joints but the shaft is at a fairly large angle so they aren’t lasting particularly long, a CV I think would sort this issue out but I’m having trouble finding something compact.

I have looked at ATVs and Quad Bike CVs but they all appear to be splined shafts with CVs built in, I need something with a flange type mount but haven’t been able to find much.

Thanks for the input so far guys it is much appreciated, I need all the help I can get on this one.

HowardB - 3/10/25 at 01:30 PM

quote:
Originally posted by DANMAN
I’m currently running uni joints but the shaft is at a fairly large angle so they aren’t lasting particularly long, a CV I think would sort this issue out but I’m having trouble finding something compact.

I have looked at ATVs and Quad Bike CVs but they all appear to be splined shafts with CVs built in, I need something with a flange type mount but haven’t been able to find much.

Thanks for the input so far guys it is much appreciated, I need all the help I can get on this one.


Can you get a spline to flange adaptor?

coyoteboy - 3/10/25 at 03:24 PM

Call/email febest. They make just about every joi t out there and they're super cheap. Toyota wanted 300 for a joint for my truck and febest had one delivered for 60, but better than that they could crosscheck mounting dims and confirm fitment by email.

obfripper - 5/10/25 at 07:38 PM

This is a 78mm od propshaft joint, but should be quite similar in torque capacity, from a volvo/ford haldex 4wd system:

https://www.driveshaftparts.com/ME733

There is an original volvo part number in the description that should help you finding a local supplier, might be worth getting the whole prop from a scrap car to have a bit of a tryout before buying new bits.
Volvo themselves only sell the prop as a complete assembly, but there are plenty of new aftermarket replacement joints.


Dave

gremlin1234 - 6/10/25 at 07:11 AM

some triumph spitfires had a cv jointed prop-shaft, I don't know the exact dimensions but maybe worth a look

https://www.canleyclassics.com/?catalogue=triumph-spitfire-mkiv/1500&diagram=triumph-spitfire-mkiv/1500-propellor-shaft
linky

DANMAN - 13/10/25 at 07:21 AM

quote:
Originally posted by HowardB
quote:
Originally posted by DANMAN
I’m currently running uni joints but the shaft is at a fairly large angle so they aren’t lasting particularly long, a CV I think would sort this issue out but I’m having trouble finding something compact.

I have looked at ATVs and Quad Bike CVs but they all appear to be splined shafts with CVs built in, I need something with a flange type mount but haven’t been able to find much.

Thanks for the input so far guys it is much appreciated, I need all the help I can get on this one.


Can you get a spline to flange adaptor?


I did look at that as an option but don't have the room unfortunately.

DANMAN - 13/10/25 at 07:27 AM

quote:
Originally posted by coyoteboy
Call/email febest. They make just about every joi t out there and they're super cheap. Toyota wanted 300 for a joint for my truck and febest had one delivered for 60, but better than that they could crosscheck mounting dims and confirm fitment by email.


I did some emailing back and forth with them a few weeks ago but they basically said I need to give them a vehicle make and model then they will do some measurements for me, I got the feeling the fellow there couldn't be bothered. I didn't expect him to go and measure every CV joint they had in stock for me, I was more just hoping that he may have gone "hang on a sec, a CV joint out of an old xxxx would probably work" which is basically what I am hoping for here.
The great thing about a forum full of people that have worked on a variety of cars for many years is that you can sometimes come across someone that has seen what you are after and point you in the right direction.

DANMAN - 13/10/25 at 07:29 AM

quote:
Originally posted by obfripper
This is a 78mm od propshaft joint, but should be quite similar in torque capacity, from a volvo/ford haldex 4wd system:

https://www.driveshaftparts.com/ME733

There is an original volvo part number in the description that should help you finding a local supplier, might be worth getting the whole prop from a scrap car to have a bit of a tryout before buying new bits.
Volvo themselves only sell the prop as a complete assembly, but there are plenty of new aftermarket replacement joints.


Dave


Ohhhh, this could be a candidate. I'll do some more measuring to see if I can make this work, might still be a bit of a squeeze.

baz-R - 14/10/25 at 11:10 AM

need to be careful how we are defining some of these joints? a true CV or Tripode (triple spherical roller on needle bearings) joint generally don't like the high rpms and fail due to the way the grease acts centrifugally.

my choice would be a UJ or failing that a LOBRO and that's the same route manufactures go down

Dave mentioned a Volvo joint that's a LOBRO and come in all sorts of sizes and 100mm is a very common size - VAG group put them in some of their 4x4 props too

J&R driveshafts are usually a font of knowledge and very reasonable for supply


J&R Trading (UK) Ltd
Unit 14 Elmdon Trading Estate
Bickenhill Lane
Birmingham, West Midlands
B37 7HE
United Kingdom
https://www.jandrcvjoints.co.uk