Zfan1 Posted July 16, 2013 Share Posted July 16, 2013 You're making this way too complicated. The shaft, and everything attached to it is aluminum. The yoke / flange is steel. Go with the 1350 U-joints. Even a 1350 front and 1310 rear (biggest that flange allows IIRC). I went with 1350 on both ends as my pinion flange is much larger than an R200 X2, that is what I did Quote Link to comment Share on other sites More sharing options...
jnjdragracing Posted July 16, 2013 Share Posted July 16, 2013 Bummer, I hate breakage. My brother Jerry in on vacatio but I will let him know what happened if he checks in. He is on a cruise.... We had our drive shaft built and had nt had any issues. I will ask him what ujoints / flanges he used. So far we have not broke ours. Just the CV's. Hopefully it is only the drive shaft, and yes drive shaft safethy loops really do help in other breakage to a minimum. John Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted July 16, 2013 Author Share Posted July 16, 2013 (edited) Pictures. Most of these are of the slip yoke damage. One picture is of the rear yoke that attaches to the diff. I painted it assembled-I'm not sure if the lack of paint on the u-joint cap indicates movement of the yoke or not.... Have DSS on my speed dial-nobody answered during lunch. Included links to some racing from that night. http://www.youtube.com/watch?v=2qF_HcPBkIg&feature=share&list=UUsYmPVA57WCEa7KNsD3Jlxw http://www.youtube.com/watch?v=_SnMypSY99k&feature=share&list=UUsYmPVA57WCEa7KNsD3Jlxw Edited July 16, 2013 by RebekahsZ Quote Link to comment Share on other sites More sharing options...
Nexgen1llc Posted July 17, 2013 Share Posted July 17, 2013 Hey buddy, we have some JB Weld at the shop (and a lift so you don't have to work on your back). Glad to see the damage was isolated to the front yoke and not to the T-56 output shaft! Enjoyed racing with you the other night! -Terry Quote Link to comment Share on other sites More sharing options...
mattd428 Posted July 17, 2013 Share Posted July 17, 2013 Looks like your slip yoke isnt far enough in the trans. From the pic looks like i twisted half way down the broken section. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted July 17, 2013 Author Share Posted July 17, 2013 Matt's-I thought about that, too. But, the driveshaft has very little space between the diff flange and the diff yoke for installation. I wonder it the yoke is too long and the driveshaft tube is too short. The total assembly is the correct length. I got the email for the driveshaft rep (Frank) at DSS today. Will start emailing him pics of the failure and new measurements tomorrow. Quote Link to comment Share on other sites More sharing options...
m1noel Posted July 17, 2013 Share Posted July 17, 2013 what have we learned from this- People with hobby cars should have short, straight, flat driveways. If you keep adding power and trying to find traction, you will always find a new week link. Hobby cars that are driven (or raced) are never finished. A few seconds of fun at the race track requires many, many hours of preparation and usually many, many hours of repairs. Money maybe does buy happiness, or at least better parts. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted July 17, 2013 Author Share Posted July 17, 2013 Sounds like advice for a newly wed couple. Especially about the hours of prep for a few moments of bliss! Anything worth doing is worth doing faster and harder and when I'm feeling good-more than once! There's always a weak lin-preferrably the track prep. Seeing how fat Ive gotten in those videos makes me feel like "the missing link." Started a diet today-maybe ill still be on it tomorrow. The weak link was the driver's fat arse. Quote Link to comment Share on other sites More sharing options...
NewZed Posted July 17, 2013 Share Posted July 17, 2013 Seems like all you really need is two new yokes. All of your damage pictures are yoke only. The yokes fit the u-joints so two new (stronger) yokes should get you back in business. I assume the twisty portion wasn't there in the beginning. Looks like the CV axles with no heat treatment. JTR may have got a batch of yokes with poor heat treatment. Quote Link to comment Share on other sites More sharing options...
mattd428 Posted July 17, 2013 Share Posted July 17, 2013 With all the parts ive broken im surprised a yoke hasnt happened yet. Quote Link to comment Share on other sites More sharing options...
SUNNY Z Posted July 17, 2013 Share Posted July 17, 2013 That was a clean break! Usually they grenade, and take out the tail housing in the trans with them. You got lucky! Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted July 17, 2013 Author Share Posted July 17, 2013 The twisted splines remind me of Sunny's axles that weren't heat treated properly. I should get the measurements done tomorrow in order to finalize plans with Frank at DSS. It has been a busy week at the office-and I've been too tired to get under the car in the evenings. I have tossed around the idea of just sourcing better yokes-anybody got a source? Anybody know if the T56 yoke is special, or can I use a standard GM yoke? My yoke has 26 splines, one is really wide. I'm gonna mark my next yoke with a straight line in sharpie so I can inspect to see if it is twisting. I love being able to visually inspect for impending failures. Quote Link to comment Share on other sites More sharing options...
mattd428 Posted July 17, 2013 Share Posted July 17, 2013 gm yoke is a gm yoke. Just did a t56 swap in a 68 chevelle from an auto same yoke just shortened the driveshaft. I have my old driveshaft if you need another one. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted July 20, 2013 Author Share Posted July 20, 2013 (edited) Videos from the night at the strip have been posted in the Motorsports forum under a title of "V8 S30s Drag Racing at Moulton on 7/13/13" or something like that. Further discussion on this subject will be in the drivetrain forum. Edited July 20, 2013 by RebekahsZ Quote Link to comment Share on other sites More sharing options...
Phantom Posted July 28, 2013 Share Posted July 28, 2013 I have 35,000 miles on my JCI driveshaft now with no issues and the car has been driven hard. It is shaft #1 so maybe it's superior in some way to later versions. I did, however, break a half-shaft u-joint on the track and that was painful. The loose half shaft tore out my e-brake and destroyed the brake caliper on the driver's side. Broke it on the shift from 1st to 2nd and still coasted thru the quarter in 20 seconds. Still thinking if there I'd a way to install hoops on the half shafts. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted July 28, 2013 Author Share Posted July 28, 2013 Yeah, I hear ya. My car has very little mileage, but it almost all involved dumping the clutch near the torque peak combined with VHT. The right foot only comes off the floor to change gears. Unfortunately, that means it almost always goes from the trailer to the jack stands. This is the most serious so far, it is usually something piddly (like brakes-hahaha). I hear you on the axle loops-on the to do list. Kind of sucks that they have to be the same spec as the driveshaft loop. Honestly, I think we should have a loop on both ends of the driveshaft and on both ends of each axle. I first built this car to be a street car, but it is just too fast to really enjoy on the street. Pushing down the go pedal is like crack. Driving this car on the street is like kissing a porn star on the cheek. Quote Link to comment Share on other sites More sharing options...
SUNNY Z Posted July 29, 2013 Share Posted July 29, 2013 Or you Nancy's could just upgrade your axles and not have to worry about them going on vacation. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted July 29, 2013 Author Share Posted July 29, 2013 Oh, that was harsh.... Somebody is all cocky from last night! I got a feelin' your parts breakin' days aren't over. Somebody with the screen name "Sunny" callin' somebody Nancy! Quote Link to comment Share on other sites More sharing options...
texis30O Posted July 29, 2013 Share Posted July 29, 2013 @RebekahsZ Sorry I have to steal a quote from you for my sig. Back to the issue at hand. I am in the process of building my LS conversion now. I am taking notes on all of the carnage that ya'll are having so that I can make sure that I do not go through the same thing. Keep us in the loop on your decision. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted July 29, 2013 Author Share Posted July 29, 2013 The newest carnage is spot weld fatigue in the panel where the RT mount bolts. It is where the panel welds to the bottom of the tranny tunnel (not the ears where the RT actually bolts). This area needs seem welding. Quote Link to comment Share on other sites More sharing options...
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