Removing and fitting uj’s

[Roscobbc]

When caps are pressed in, it‘s quite possible that the yoke becomes fractionally squeezed (particularly the outer driveshaft one). This will obviously affect how the caps sit and the float/ tightness of the UJ.

btw, to gauge any difference in thickness of the clips, close the verniers onto the old clips, then without moving the vernier jaws, see if the new clips slip in! You don’t need to read it. When I did my apprenticeship we weren’t allowed to use a digital vernier or micrometer - that was cheating! It was the original type where you look for the aligned marks. I’ve still got an old school one and it is a struggle to see the marks these days!

Verniers are great for quick repetitive measurements but for real accurance down to 'tenths of a thou' (sorry used proper English measurements.....none of that foreign metric crap!)

 

[teamzr1]

Kinda on the same subject

Some years back I was getting ready to do a 100-mile Open Road Race through the high elevation
very windy road of mountain out of Battle Mountain Nevada
I wanted to change the gear ratio of the rear end but not having time I took it to a shop I never used before

With about 10 miles into the race doing over 170 MPH, even wearing a full face helmet and earplugs
I heard a big bang and my Snakeskinner ZR-1 was all over the road and freewheeling downgrade from
6,500 feet to 4,500 feet
I could hear loud banging,
maybe due to all the years of racing I go the car slowed down and had to pull over into sagebrush and boulders

When I was able to get the car jacked up and got under there I found the driveshaft U-joint had come off the
yoke of the diff
I found the shop that did the work never tighten down the 2 mounting straps to bolt the u-joint to the yoke !

So at that speed the end of driveshaft was bouncing off the ground and lucky it did not hit a hole in the road
causing it to heave the car up and over :-(

 

[Mad4slalom]

When caps are pressed in, it‘s quite possible that the yoke becomes fractionally squeezed (particularly the outer driveshaft one). This will obviously affect how the caps sit and the float/ tightness of the UJ.

btw, to gauge any difference in thickness of the clips, close the verniers onto the old clips, then without moving the vernier jaws, see if the new clips slip in! You don’t need to read it. When I did my apprenticeship we weren’t allowed to use a digital vernier or micrometer - that was cheating! It was the original type where you look for the aligned marks. I’ve still got an old school one and it is a struggle to see the marks these days!

Thanks, so is it best to emmery cloth the yoke holes so that the caps at least feel that they start to enter the holes before committing to pressing them in?

 

[Mad4slalom]

Kinda on the same subject

Some years back I was getting ready to do a 100-mile Open Road Race through the high elevation
very windy road of mountain out of Battle Mountain Nevada
I wanted to change the gear ratio of the rear end but not having time I took it to a shop I never used before

With about 10 miles into the race doing over 170 MPH, even wearing a full face helmet and earplugs
I heard a big bang and my Snakeskinner ZR-1 was all over the road and freewheeling downgrade from
6,500 feet to 4,500 feet
I could hear loud banging,
maybe due to all the years of racing I go the car slowed down and had to pull over into sagebrush and boulders

When I was able to get the car jacked up and got under there I found the driveshaft U-joint had come off the
yoke of the diff
I found the shop that did the work never tighten down the 2 mounting straps to bolt the u-joint to the yoke !

So at that speed the end of driveshaft was bouncing off the ground and lucky it did not hit a hole in the road
causing it to heave the car up and over :-(

Scary! I had one let go on an mgb gt I borrowed from my sister , luckily it goes through the crossmember so was just spinning around in there, shocking noise tho it actually made me think of making a propshaft Shielding crossmember as I think some racers do to keep that spinning lump of steel from smashing up yr nice fibreglass floors

 

[Roscobbc]

Kinda on the same subject

Some years back I was getting ready to do a 100-mile Open Road Race through the high elevation
very windy road of mountain out of Battle Mountain Nevada
I wanted to change the gear ratio of the rear end but not having time I took it to a shop I never used before

With about 10 miles into the race doing over 170 MPH, even wearing a full face helmet and earplugs
I heard a big bang and my Snakeskinner ZR-1 was all over the road and freewheeling downgrade from
6,500 feet to 4,500 feet
I could hear loud banging,
maybe due to all the years of racing I go the car slowed down and had to pull over into sagebrush and boulders

When I was able to get the car jacked up and got under there I found the driveshaft U-joint had come off the
yoke of the diff
I found the shop that did the work never tighten down the 2 mounting straps to bolt the u-joint to the yoke !

So at that speed the end of driveshaft was bouncing off the ground and lucky it did not hit a hole in the road
causing it to heave the car up and over :-(

Many years ago when at technical college I was running a modified MK3 Zephyr 6, my buddy was running a PA Cresta. One Saturday afternoon he had the front end of a prop shaft fail, drop on the ground while driving. It 'dug-in', pole vaulting the rear end in the air and (before seat belts were mandatory) threw him on to the dash board. Should have seen the bruises to his face!

 

[Forrest Gump]

Thanks, so is it best to emmery cloth the yoke holes so that the caps at least feel that they start to enter the holes before committing to pressing them in?

I wouldn’t emery the yoke bores unless there was an obvious burr or ding that needed removing. Compare the size of the new and old caps. If the diameters of the new parts are right, they’ll go together, just keep everything square as you press them in. If the clips were too thick maybe the caps are wrong too??!!

 

[teamzr1]

Scary! I had one let go on an mgb gt I borrowed from my sister , luckily it goes through the crossmember so was just spinning around in there, shocking noise tho it actually made me think of making a propshaft Shielding crossmember as I think some racers do to keep that spinning lump of steel from smashing up yr nice fibreglass floors

You're right
I had to fashion a way to prevent the back end of the driveshaft from being able to drop down to the ground
as once was once too often :-(

Snakeskinner ZR-1 from the bottom
I have to admit now, as they say if you're not cheating, you're not winning
Notice the different sized holes drilled in the frames to reduce weight

That is a very, very expensive British Hewland, they love American dollars

Notice the bends in the headers

 

[teamzr1]

Many years ago when at technical college I was running a modified MK3 Zephyr 6, my buddy was running a PA Cresta. One Saturday afternoon he had the front end of a prop shaft fail, drop on the ground while driving. It 'dug-in', pole vaulting the rear end in the air and (before seat belts were mandatory) threw him on to the dash board. Should have seen the bruises to his face!

C4s had a common problem with the half shafts coming out the diff, so we made the groove cuts wider and would double up on the C-clips
Problem was even tougher for my racer as seen below, at first went with Hewland making the tranny was using a flywheel weighing only 7 pounds and a Tilton 5 discs with floaters (later had George Mcleod do a flywheel that really was a starter ring with a custom dual with floaters clutch

In this case when shaft dropped I went to downshift, the Hewland is an odd dog, rarely use the clutch and have to blip shift by RPMs matching
but I went to downshift hoping to have the engine drag down the RPMs, not knowing the shaft was high RPM spinning while bouncing off the ground :-(
there was no inertia /mass of the flywheel to drag the RPMs down

 

[Mad4slalom]

Many years ago when at technical college I was running a modified MK3 Zephyr 6, my buddy was running a PA Cresta. One Saturday afternoon he had the front end of a prop shaft fail, drop on the ground while driving. It 'dug-in', pole vaulting the rear end in the air and (before seat belts were mandatory) threw him on to the dash board. Should have seen the bruises to his face!

Eek horrendous !

 

[Mad4slalom]

You're right
I had to fashion a way to prevent the back end of the driveshaft from being able to drop down to the ground
as once was once too often :-(

Snakeskinner ZR-1 from the bottom
I have to admit now, as they say if you're not cheating, you're not winning
Notice the different sized holes drilled in the frames to reduce weight

That is a very, very expensive British Hewland, they love American dollars

Notice the bends in the headers

View attachment 24709

Serious race car, I met the man who made those headers once, it was at some race event birthday party as I recall ,..…..
He was making those girraffes and poodles out of stretchy balloons !!!

 

[Mad4slalom]

I wouldn’t emery the yoke bores unless there was an obvious burr or ding that needed removing. Compare the size of the new and old caps. If the diameters of the new parts are right, they’ll go together, just keep everything square as you press them in. If the clips were too thick maybe the caps are wrong too??!!

I will check the sizes of both with the vernier thanks