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The discussion driveshafts and u-joints has me thinking on what to do with mine, both on the 77 and 69. What I know is my Ramadei differential is not good for much over 450 HP. .....according to Gary, so none of the other drivetrain needs to exceed that. As we know......you can move the weak link around.....but there is a weak link somewhere. The other factor for me is that despite having 560 HP / 565 ft. lbs a torque, and whatever Mark Jones builds into my BBC........those numbers mean nothing if I never push the car to that point. But without those numbers at the high end.....I would NOT have the numbers where I need them....so, its just what it takes. I really don't think I will have any driveline problems, so not going to start re-designing the driveshafts and u-joints. I need to talk to Gary. After some recent discussions with Jody Haag.....I may not even need to shorten my driveshaft for the M23Z transmission and QuickTime bellhousing.....so in that case.....I will use the stock rebuilt 77 driveshaft as is.
I was really happy with how well my new flange tool worked today. Since I had 4 half-shafts, I could tell 2 had tight u-joints. On closer inspection there were 4 ways I could tell that 2 of my 4 flanges were bent:
U-joints did not rotate freely, just too tight, binding
When put flat to flat you could see an air gap at the ends and they would rock, the good ones did not.
They also rocked on the ultra flat flange tool, and an air gap was visible under the bolts.
They measured differently. There are machined flats that GM must have used for something when new (installation?). The good joints measured 2.450" as in the pic below between those machined flat areas. The 2 tight ones were .030 to .050" tighter than that.
So I even used the flange tool to straighten the bent flanges. Mine is 1.25" thick so it's more than strong enough. I kept putting more & more folds of aluminum foil in the center (.038") and tightening them down, until they were good. Aluminum foil is around 1/2 to 1 thousandths of an inch thick, depending on the brand. I just kept folding it.
If you do not have a flange tool, you could also bolt them to the axle flange, or 2 of them together, and add some shims, and straighten them that way. I just went slowly so as not to bend them to far the other way.
Next is paint. And then the flange tool will help again when I tap in the u-joint caps.
You can see my aluminum foil shims, (about .038") and my final measurement, some of the bolts are loose here.
Hey Jeff, I do not need the 2-1/2" half-shaft set. I will keep the 3" set. You can have first dibs if you want them. Brand new solid spicers. Painting tommorrow. They are absolutely bare metal here, any pitting very minor and barely visible, like at 6" distance to see it..
Last edited by leigh1322; Jan 15, 2023 at 09:52 PM.
I was really happy with how well my new flange tool worked today. Since I had 4 half-shafts, I could tell 2 had tight u-joints. On closer inspection there were 4 ways I could tell that 2 of my 4 flanges were bent:
U-joints did not rotate freely, just too tight, binding
When put flat to flat you could see an air gap at the ends and they would rock, the good ones did not.
They also rocked on the ultra flat flange tool, and an air gap was visible under the bolts.
They measured differently. There are machined flats that GM must have used for something when new (installation?). The good joints measured 2.450" as in the pic below between those machined flat areas. The 2 tight ones were .030 to .050" tighter than that.
So I even used the flange tool to straighten the bent flanges. Mine is 1.25" thick so it's more than strong enough. I kept putting more & more folds of aluminum foil in the center (.038") and tightening them down, until they were good. Aluminum foil is around 1/2 to 1 thousandths of an inch thick, depending on the brand. I just kept folding it.
If you do not have a flange tool, you could also bolt them to the axle flange, or 2 of them together, and add some shims, and straighten them that way. I just went slowly so as not to bend them to far the other way.
Next is paint. And then the flange tool will help again when I tap in the u-joint caps.
You can see my aluminum foil shims, (about .038") and my final measurement, some of the bolts are loose here.
Hey Jeff, I do not need the 2-1/2" half-shaft set. I will keep the 3" set. You can have first dibs if you want them. Brand new solid spicers. Painting tommorrow. They are absolutely bare metal here, any pitting very minor and barely visible, like at 6" distance to see it..
Leigh.....PM me with a price. If I take them you don't need to paint them, I will most likely get them powdercoated. However,.....I am considering holding out for 3 inch shafts, so not sure what I am doing.
Last edited by Shovels and Vettes; Jan 15, 2023 at 10:31 PM.
What transmission slip yoke and u joints are you running on your current set up?
I have a current thread going right now titled “Transmission Tunnel Mods for 1330 U Joints”, which has some good discussions you may want to read.
I also just ordered a new DynoTech, balanced chrome moly driveshaft built with a 1350 transmission slip yoke and Spicer solid u joints and 1330 differential solid Spicer u joints. $595.00
It adds some strength to the drivetrain and cheap insurance that nothing will come apart when I’m out on a nice weekend drive with the wife.
Don’t forget you’re putting some good torque to the ground when your rolling along the highway and mash the go pedal down, or accelerate through that twisting mountain curve.
What transmission slip yoke and u joints are you running on your current set up?
I have a current thread going right now titled “Transmission Tunnel Mods for 1330 U Joints”, which has some good discussions you may want to read.
I also just ordered a new DynoTech, balanced chrome moly driveshaft built with a 1350 transmission slip yoke and Spicer solid u joints and 1330 differential solid Spicer u joints. $595.00
It adds some strength to the drivetrain and cheap insurance that nothing will come apart when I’m out on a nice weekend drive with the wife.
Don’t forget you’re putting some good torque to the ground when your rolling along the highway and mash the go pedal down, or accelerate through that twisting mountain curve.
The reason I ask is that for the past 5 years I’ve been trying to convince myself that the 1310 transmission yoke that came with my SST conversion kit would hold up to my engine’s torque.
The experts said they would hold up on a street car as long as I wasn’t planning to drive it hard.
Recently my thoughts have gone to, “what if I want to get on it some time”.
Do I want to always worry about breaking a u joint?
I don’t, so I recently decided to upgrade them to something stronger.
If your current set up is 1330’s front and rear, you should be ok.
If you currently have 1310’s, you might consider upgrading.
Last edited by OldCarBum; Jan 16, 2023 at 07:58 PM.
The reason I ask is that for the past 5 years I’ve been trying to convince myself that the 1310 transmission yoke that came with my SST conversion kit would hold up to my engine’s torque.
The experts said they would hold up on a street car as long as I wasn’t planning to drive it hard.
Recently my thoughts have gone to, “what if I want to get on it some time”.
Do I want to always worry about breaking a u joint?
I don’t, so I recently decided to upgrade them to something stronger.
If your current set up is 1330’s front and rear, you should be ok.
If you currently have 1310’s, you might consider upgrading.
I called Gary today and discussed it this morning. My 77 has 1330's front and rear on the driveshaft ...so should handle it fine with the Mark Jones 408 build. Of my two cars....the 77 will be the one I might push harder and higher RPM....because its a small block.
As for the 69, I don't have a good drive shaft right now...BUT, Gary built my differential with 1310 pinion....and I am not pulling it and changing it now. So....I might as well stick with 1310 on the front of the driveshaft. The Mark Jones 468 big block is NOT going to be a max power build, and I simply will NEVER drive the car like some of you will.....I just have no interest in high rpm, clutch pedal sidesteps, spinning tires, or anything even remote. I am building a big block for big low end torque.....smoothly. And remember....the Gary Ramadei built differential is only good to 450 HP anyways.......his words. Although, his son blew up parts with a 350.....so it really is about how you drive the car. I will never race, never drag strip, never hammer on it by most peoples definition. I will accelerate quickly at times, but smoothly. So.....Gary and I agreed today that the 1310 u-joints on the 69 Big Block will be just fine. He reminded me that those 1310 u-joints were used on L88's back in the day. All of this really comes down to how you drive.....and I just do not abuse my machines...none of them.
The rabbithole sucks big time......but I am drawing lines in the sand. I still am pissed I have this Quictime bellhousing which is absurdly overkill. IT better dial out good....cause thats one of the reasons I stuck with it. The big block bellhousing will be aluminum 621 ......probably the American made one, from California...or the SST version. It will be good enough.
Sorry Leigh....don't want to hijack your build thread.
Last edited by Shovels and Vettes; Jan 16, 2023 at 09:02 PM.
Jeff I get it.
The three of us are doing somewhat similar BB builds right now. But that does not mean they will be exactly the same.
Greg's is a 496 TQ monster. My BB is a 6500 rpm capable screamer. And I intend to drive it hard. I may drag it just to see what it'll do. And I will probably autocross it a couple times. Autocrossing for me, after my Pro-Solo days, means some serious powerslides, and a lot of full throttle. I drove very "loose" back then, but it was fast! I know me. I will eventually drive it like that. I still have not decided whether I will go with 285 Z rated tires or not, but probably. And I do not want to have to worry about parts breakage. So I am going to follow Greg's lead and go with a 1350/1330 chrome moly 2.5" driveshaft. That is what it will take to give me piece of mind for my driving style. I will be cruising mostly, and I know I won't be able to get on it hard on the street, for long, but I still want it to be track capable when & if I put it on a track. 'Cause that's where my background is.
If I did build a dedicated auto cross car it would be something my wife could enjoy driving as well.
But she really likes the idea of building another Factory Five Racing 33 hot rod or an older Jeep.
I will admit, I should have kept my FFR hot rod because it out performed my C3 in every aspect.
Love this Thread! Appreciate the details shared and solutions to problems.
I used to have a small powder coating biz. There is a way to 'patch' your removed powder from your frame and its DIY with a few cheapish tools. You could POR15 the bare areas and no one would be the wiser - except you. If you did want to touch up the powder you could buy a cheap HF gun and apply it yourself. An excellent ground is mandatory, as in running a wire to your house grounding rod for best results. Fog the powder on and use heat lamps to cure. IIRC a generic black powder wants 375*- 400* PART TEMPRATURE for 15-20 minutes. Being fairly small areas it shouldn't be difficult. If it were me I'd put some sort of shelter around the area while applying the heat to trap that in and accelerate cure time. The nice thing about black is its nearly impossible to overcure. If you could only get it to 300 hypothetically you can just up the cure time. Powder manufacturer can provide you with cure tables. OORRRR, there is a liquid you can mix with your powder and apply with a brush. I don't recall the product name at the moment, but it would be cheaper than setting up a cheap powder gun and less frustrating. I'm guessing you'd run into faraday issues with previously applied powder, which you could also 'hot flock' by warming up the part prior to shooting the powder. Say 150-200* but good cosmetic results on a patch attempt may not be great.
Shooting powder again over repaired areas will nearly always be noticeable. Sort of like using a spray can over proper paint. It will look like overspray, which is where brushing it on would alleviate that, but that finish most likely would not be as smooth as the surrounding area. The only way I know of to make it perfect again is to have a pro shop reshoot it. They will have guns costing $4k+ and are made to do what you need. On the bright side they will not have to remove the old powder to do it, just shoot over it after a good wipe down.
You'd be surprised what you can do with even a cheapy Harbor Freight gun. Your biggest restraint will be your oven size (haul away replacements can be had for $50). Put a 240v outlet in your shop, run a ground and before long nearly every small metal object on your Vette will be powder coated from brackets to bolt heads!
Just to finish up on the u-joint install, in case anyone needs some tips:
My 2 bent flanges measured 2.390" at the yellow arrows vs 2.450" for all the other flanges at the other 10 joints, and did not rotate smoothly. Because the flange bent "inwards" I knew it happened during installation of the u-joint caps. This inward bending is what convinced me I needed to use the flange tool.
The flange is very thin where the red arrow is. There is also a protrusion, that is why the flange tool needs a recess. The red arrow is where the flange MUST be supported during cap installation or it will bend again.
Here is a close up of the flange mounting tool. It needs a recess in the center. You already have this same shape on the axle shafts, and it is possible you could use that. But the tool is available on-line for only $40
This is how I installed the u-joints: I placed everything in the vise like this.
Th caps must be removed to install. I prefer to install them horizontally like this to make absolutely sure the needles remain in place. The caps push in this far by thumb power. I made sure the u-joint crossbar slid in/out of the cap easliy.
So with the correct size socket (21mm) it only took some LIGHT TAPS from my brass hammer to set them far enough into the flange. But as light as those taps were, I would not be surprised if they would bend the flange if they were done WITHOUT the flange support.
The c-clips go in with needle nose pliers. Make sure the c-clips are inside the groove in 3 spots or they will come out. And then give a gentle tap from both sides to make sure the caps are centered & settled against the c-clips. The c-clips need to look the same on both sides. They actually protrude just slightly in the center when they are under pressure.
I would NEVER use a press on these things because they bend so easy. And my machine shop always uses a press and said they hate working on painted parts because they always get scratched.
So you can ABSOLUTELY do a better job at home, with hand tools, than the machine wants to bother with.
The remaining joint caps get lightly tapped in on a flat table, no special tools required except a 21mm socket and a hammer. The joints are snug but move with strong thumb pressure.
DONE!
Last edited by leigh1322; Jan 22, 2023 at 02:21 PM.
Great information Leigh,
Since I don’t have drinking buddy’s with a machine shop, I definitely need to buy a flange mounting tool.
Do you have a link for the correct tool?
Don’t forget to make sure the c-clips are installed correctly.
Just an FYI,
My new driveshaft should be delivered by FedEx today.
I’ll post you up a picture.
Last edited by OldCarBum; Jan 23, 2023 at 03:31 PM.
That looks great!
I am still trying to catch him on the phone to order a duplicate of that. Resorting to e-mail now. That means you got ahead of me!
Hmmm... but my motor and frame are already done and waiting. We'll see who's first! LOL
Let me know how it fits!
Try his direct line number that is attached to the email I posted.
He seems to answer that over the number listed on line.
Our first contact was through email, which he said was the best way, because he does more business through email than by telephone.
Once you get ahold of him he is very responsive.
I guess he is very busy.
Oh boy!
It's like Christmas again today!
It looks so good.
And fresh leather smells so good also.
Leather wrap courtesy of Chuck Pelton online here.
He added a little padding too, it is 1.1" to 1.2" in grip diameter.
And it feels great!
I had considered going smaller to a 14" wheel, but this is my original and will do fine now.
I spent 27 years hanging onto the wheel in autocross, and the feel of it is so important.
Somebody please measure the width of a stock rim for me, I wish I had before. It just seemed so thin. This one feels better.
I will keep the 3" half shafts for my car.
That awful looking yellow paint was really tough and it would not even sandblast off, so I had to chemically strip them.
Well after that messy job, they came out looking almost brand new! That was some tough paint!
They only had a small amount of rust on them. But there are hardly any scratches in the shiney steel.
So that gave me another idea.
If I can get the last bit of rust off I think they would look just beautiful clear coated.
I had to build a little wood box to hold them submerged in 1-1/2 gallons of Evaporust.
What do you think?
Last edited by leigh1322; Jan 25, 2023 at 10:11 PM.
