12 bolt conversion
Thread Starter
Burning Brakes
Joined: Nov 2011
Posts: 1,170
Likes: 201
From: Willoughby Ohio
He had to destroy the fastener to get the clamp to bend. The 1350 clamps are heavier so I would definitely say the fastener will break first.
I now have what is needed to make every corvette specific application.
The plan is to get all bases covered first and go from there.
Stock components in good shape usually hold up to 350 hp with street tires. Add sticky tires and that may change.
Racer
Joined: Dec 2014
Posts: 328
Likes: 30
Mike tested the 1330 clamp which is the 1st one shown in this thread.
He had to destroy the fastener to get the clamp to bend. The 1350 clamps are heavier so I would definitely say the fastener will break first.
I now have what is needed to make every corvette specific application.
The plan is to get all bases covered first and go from there.
Stock components in good shape usually hold up to 350 hp with street tires. Add sticky tires and that may change.
He had to destroy the fastener to get the clamp to bend. The 1350 clamps are heavier so I would definitely say the fastener will break first.
I now have what is needed to make every corvette specific application.
The plan is to get all bases covered first and go from there.
Stock components in good shape usually hold up to 350 hp with street tires. Add sticky tires and that may change.
I think i will have 350-400 with pilot spot 4 tyres.
I have 1330 on the spindle ends and 1350 on the diff end.
the original unis that need replacing. One of the 1350 to 1330 ends have been replaced but you can only get them with grease fittings.
But they have the original straps and bolts... i went and got some new Allen key bolts to replace the bolts as some were starting to round.
What would you upgrade for my power ?
Thread Starter
Burning Brakes
Joined: Nov 2011
Posts: 1,170
Likes: 201
From: Willoughby Ohio
The fastener I was describing was a 5/16 bolt. The bolt was tightened to the point that it twisted in order to effect the part. I am guessing you have the dana 44 in an 80 to 82. I would upgrade as much as possible due to the carnage if something lets loose. What size bolt goes in your 1330 size axle?
Racer
Joined: Dec 2014
Posts: 328
Likes: 30
The fastener I was describing was a 5/16 bolt. The bolt was tightened to the point that it twisted in order to effect the part. I am guessing you have the dana 44 in an 80 to 82. I would upgrade as much as possible due to the carnage if something lets loose. What size bolt goes in your 1330 size axle?
I can either upgrade to uni to 1330 spicer HD non greasable uni and upgrade the strap, drill and tap the flange to accept 5/16" or change out the flange to a manual 80-82. Drilling out would be cheaper...
I would then have 1350 straps and 5/16" bolts on the diff end. Will these be ok or do they need upgrading to ? Then the "weak" point may be the greasable conversion uni
Race Director
Joined: Nov 2006
Posts: 19,445
Likes: 353
From: Athens GA
St. Jude Donor '12-'13, '15- '16-'17-'18-'19, '21
Nice.
Not sure if you answered this yet...the straps you are making...are they threaded to replace the u bolt type of u joint fasteners? If so, what is the thread size? I imagine the bolt comes in from the back side. So does that require drilling out the hole to a larger size? A nice hardened cap screw and lock washer or loctite would work. Right?
Good pics
Txs
Bman
Not sure if you answered this yet...the straps you are making...are they threaded to replace the u bolt type of u joint fasteners? If so, what is the thread size? I imagine the bolt comes in from the back side. So does that require drilling out the hole to a larger size? A nice hardened cap screw and lock washer or loctite would work. Right?
Good pics
Txs
Bman
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Thread Starter
Burning Brakes
Joined: Nov 2011
Posts: 1,170
Likes: 201
From: Willoughby Ohio
A little more technical information for all the big block guys.
The last part is heat treated 4150 and weighs 63.5 grams vs 72.5 grams for the factory cast piece. I will be checking out the ability of both parts today in respect to drive line angle. Not a 12 bolt part but I did get a request to make.
The last part is heat treated 4150 and weighs 63.5 grams vs 72.5 grams for the factory cast piece. I will be checking out the ability of both parts today in respect to drive line angle. Not a 12 bolt part but I did get a request to make.
Safety Car
Joined: Aug 2000
Posts: 3,909
Likes: 26
From: Clymer PA
I'm curious if there is a reason why there aren't "ears" on the cap like there are on the yoke part? I know they do not come from the factory with them as such. Having them on the cap would definitely make it harder for the u-joint to ride up over the ears causing a failure. Is there a way to machine a set that do have the "ears" incorporated?
Thread Starter
Burning Brakes
Joined: Nov 2011
Posts: 1,170
Likes: 201
From: Willoughby Ohio
It could be done but I do not believe is needed. The fit to the axle is the same as the pinion yoke and when you add the 3/8 bolts it should be pretty tough. Adding some loctite to the bolts would be cheap insurance.
Adding the tabs would just make the part more expensive with no real value IMO. Also with new part you have 180 degrees of clamping surface and the other side is fully supported by the axle.
Adding the tabs would just make the part more expensive with no real value IMO. Also with new part you have 180 degrees of clamping surface and the other side is fully supported by the axle.
Last edited by 76strokervette; Nov 24, 2017 at 04:57 PM. Reason: spelling
Thread Starter
Burning Brakes
Joined: Nov 2011
Posts: 1,170
Likes: 201
From: Willoughby Ohio
The head of the bolt is what limits the angle on the stub axle. With a set of 12 point arp bolts the new part will allow a larger drive line angle.
Best case made for cast stock part is 60,000 psi tensile strength. The 4150 in new part is 140,000 psi tensile strength.
Best case made for cast stock part is 60,000 psi tensile strength. The 4150 in new part is 140,000 psi tensile strength.
Thread Starter
Burning Brakes
Joined: Nov 2011
Posts: 1,170
Likes: 201
From: Willoughby Ohio
I chose the spicer solid u-joint as the model for these parts due to the fact it is most often recommended. The quality control on the spicer parts is usually very good also. I am pretty sure the caps are ground which is why you can get a metal to metal seal. I looked for moroso u-joints and could not find them. Where are you getting them out of curiosity?
Team Owner
Joined: Sep 2002
Posts: 38,351
Likes: 2,077
From: California
I chose the spicer solid u-joint as the model for these parts due to the fact it is most often recommended. The quality control on the spicer parts is usually very good also. I am pretty sure the caps are ground which is why you can get a metal to metal seal. I looked for moroso u-joints and could not find them. Where are you getting them out of curiosity?
Last edited by TCracingCA; Dec 2, 2017 at 09:45 PM.
Team Owner
Joined: Sep 2002
Posts: 38,351
Likes: 2,077
From: California
I transferred this over from the under the Christmas tree thread! You can see I had the Super 10 post on a lathe, but haven't started contouring the windows etc yet toward polishing!
On the 12 bolt set up, I was grinding to polish the old fashion way, but only started that! Some pieces aren't in the picture!
"""
And from the Garage are Current projects I have out that I would like to get finished for Christmas!
In the back is the 12-Bolt Conversion with the last set sold from Tom's of true 4340 steel 30 spline inner & outer Axles in 1480 u-joint size! Going in my C2 Racer!
The front unit is a Super 10-Bolt with 30 spline inner and outer Axles in 1350 u-joint size and I have the Billet bolt on u-joint plates, but forgot to show those here! Going in my C3 Autocross car!
Well actually I have one 1480 and a 1350 in the front and back on each in the picture!
I already have another Super 10 in the race car, but moving that into a 3rd C2 Slalom car I have!
Heat treated spiders, and special crossshafts, etc., All drilled for 1/2 inch long studs!
A Virgin never used 1972 4-series case for the 12-bolt!
The sign is the actual shop rate sign out of Guldstrands second to last shop!
Hope everyone else can add more cool stuff to your rides! """"
On the 12 bolt set up, I was grinding to polish the old fashion way, but only started that! Some pieces aren't in the picture!
"""
And from the Garage are Current projects I have out that I would like to get finished for Christmas!
In the back is the 12-Bolt Conversion with the last set sold from Tom's of true 4340 steel 30 spline inner & outer Axles in 1480 u-joint size! Going in my C2 Racer!
The front unit is a Super 10-Bolt with 30 spline inner and outer Axles in 1350 u-joint size and I have the Billet bolt on u-joint plates, but forgot to show those here! Going in my C3 Autocross car!
Well actually I have one 1480 and a 1350 in the front and back on each in the picture!
I already have another Super 10 in the race car, but moving that into a 3rd C2 Slalom car I have!
Heat treated spiders, and special crossshafts, etc., All drilled for 1/2 inch long studs!
A Virgin never used 1972 4-series case for the 12-bolt!
The sign is the actual shop rate sign out of Guldstrands second to last shop!
Hope everyone else can add more cool stuff to your rides! """"
Thread Starter
Burning Brakes
Joined: Nov 2011
Posts: 1,170
Likes: 201
From: Willoughby Ohio
I believe the girdles you are talking about are made of billet aluminum.
My personal opinion is I would not use them on a street car due to fatigue strength.Surface prep on aluminum parts in a high stress environment is very important. An engineer friend and I had a conversation about this a few months ago. A stress fracture was caused by pits in the anodized surface which ended up bringing a helicopter down. The 1350 pinion yoke shown in this thread is a Mark Williams pc.
My personal opinion is I would not use them on a street car due to fatigue strength.Surface prep on aluminum parts in a high stress environment is very important. An engineer friend and I had a conversation about this a few months ago. A stress fracture was caused by pits in the anodized surface which ended up bringing a helicopter down. The 1350 pinion yoke shown in this thread is a Mark Williams pc.
Thread Starter
Burning Brakes
Joined: Nov 2011
Posts: 1,170
Likes: 201
From: Willoughby Ohio
I'm curious if there is a reason why there aren't "ears" on the cap like there are on the yoke part? I know they do not come from the factory with them as such. Having them on the cap would definitely make it harder for the u-joint to ride up over the ears causing a failure. Is there a way to machine a set that do have the "ears" incorporated?
In a completely machined part this could easily be done and make sense.