Zfan1 Posted April 20, 2014 Share Posted April 20, 2014 I found 4 of the 300 zxt axles in Ft.Worth last year for 150 bucks. Took them home and cleaned them up (rebuild) for future spares. They are getting harder to find. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted April 20, 2014 Author Share Posted April 20, 2014 ZFan1-Where did yours break? Both of SunnyZs broke same as mine: driver side on the stub between the splines and the inner CV. Mine were fine until I switched from 26" to 28" tires (unless the crack started earlier). What tire were you running and where did the failure (s) occur mechanically? Quote Link to comment Share on other sites More sharing options...
Zfan1 Posted April 21, 2014 Share Posted April 21, 2014 Snapped one drivers side and a passenger side one time just to keep things equal..lol Snapped both around 3-5" out on the actual shaft of the CV axle. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted April 21, 2014 Author Share Posted April 21, 2014 Dang! Ever seen the actual CV come apart? Quote Link to comment Share on other sites More sharing options...
Zfan1 Posted April 21, 2014 Share Posted April 21, 2014 Nope, my axles were snapped clean. I have pictures somewhere, will post if I can locate them. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted April 28, 2014 Author Share Posted April 28, 2014 (edited) Went junk-yarding yesterday and came home with two sets of spare axles. I chose the axles based on which Z31Ts had the rearend jacked up already. The first set of axles look good with intact boots. the second car had bad rear wheel bearings and there was lateral play in the hubs. Perhaps that is why the grease caps are bend to death? This was a stock Z31T with no suspension mods, so it looks like under certain circumstances, the axles can bottom out even on a Z31! I will have to disassemble the damaged axles to see if there is anything that I can use. Will go ahead and build up another complete set of shortened axles from the set of spares that had good boots. Here's a related question. Watch the attached movie-does that amount of slack in the driveline look excessive? The setup for this video is one rear tire off the floor (the other is ON the floor), car in gear. Subject diff is an R200 CLSD with Z31T CV axles. Tranny is a T56. What do you guys think, do I need to tear down my diff and check backlash in the R&P, or does this look like the normal amount of drivetrain slack for a manual tranny? Hopefully the video will load and play for you... Slack.MOV Edited April 28, 2014 by RebekahsZ Quote Link to comment Share on other sites More sharing options...
Phantom Posted April 28, 2014 Share Posted April 28, 2014 Were you able to look at the driveshaft to see how much of the movement was in it or was this all differential? I'm going to have my car in the air Wednesday doing a thorough drivetrain inspection. If I remember I'll do the same test on mine to see how it compares. Only real difference in our set-ups is that I have the u-joint halfshafts instead of the CV's. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted April 28, 2014 Share Posted April 28, 2014 That's a really crappy way to try and check backlash. I wouldn't do anything at all based on that. You could pull the driveshaft and see what it does when connected to the trans, and then pull the CVs and try to feel the backlash at the pinion, but even that is hard to do because of the resistance of the pinion seal. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted April 29, 2014 Author Share Posted April 29, 2014 (edited) OK, good, you guys can see the movie. JM-of course, I know it's ghetto, but if I don't take some shortcuts, my car will get no track time at all this summer! I'm just hoping a brother will throw a jack under one wheel and share his results for comparison's sake. I am not an expert at driveline repair, but I sure seem to be an expert at tearing parts down just to find out that they are fine. I think what I'm seeing is just the additive effect of lash in the tranny, driveshaft, diff, output stub splines, CVs, and companion flange splines. I would call this "total driveline backlash." I'd like to see if it is excessive before I start looking at individual components, and you can be sure that the first individual component I will check is the diff, then I'll try to do it correctly. I have a buddy with a non-Z drag car with a solid spooled 9" axle and an auto trans-he had almost no total driveline backlash-does that mean my stuff is goofed up, or is it not a fair comparison??. Phantom, I look forward to your findings, plus the findings of anybody else who is willing to check. Only three tools are required: a jack, a sharpie, and a smart phone camera. Edited April 29, 2014 by RebekahsZ Quote Link to comment Share on other sites More sharing options...
Phantom Posted April 30, 2014 Share Posted April 30, 2014 (edited) RebekahsZ - Did the same test you did. T56 in 1st gear, passenger rear wheel off the ground and drivers side on the ground, R200 LSD with u-joint halfshafts. Watch the valve stem closely. Total rotational movement less than 1". Something is definitely not what it should be in yours with that much difference. Real reason we were jacking the car was to find the source of a low speed, low load vibration/rattle in the rear end. Turns out that both the bolts holding the R200 to the mustache bar were loose enough to be able to turn the lock washers by hand. Oops. Tightened them up good and noise is no more. Happy camper here. IMG_4019.MOV Edited April 30, 2014 by Phantom Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted May 5, 2014 Author Share Posted May 5, 2014 Just out of curiosity I counted timeslips. And if I haven't misplaced any slips, that inner CV gave me 145 passes on slicks with 435#rwtq. I am going back to 9" Hoosiers but staying at 28" diameter. Quote Link to comment Share on other sites More sharing options...
Ylo73z Posted May 26, 2014 Share Posted May 26, 2014 I run the hoosier quick time pros on the street , 26x8 ...they hook pretty good but I want to do a mini flare and try and get a 10" hoosier under there Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted August 25, 2014 Author Share Posted August 25, 2014 Just blew outer CV of same axle-now I've broken both ends. Tear down and inspection tomorrow night-time to use that spare I have had sitting around. Broken almost literally getting groceries. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 25, 2014 Share Posted August 25, 2014 Broken almost literally getting groceries. After how many drag strip passes? What you were doing the last time might not matter so much as the history... Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted August 25, 2014 Author Share Posted August 25, 2014 Oh yeah, I know. This outer CV had 145 passes and was mated to the broken inner CV I replaced a few months ago with one of your shafts in between them. Really mostly jackstand time since then. Quote Link to comment Share on other sites More sharing options...
SUNNY Z Posted August 25, 2014 Share Posted August 25, 2014 Hah! 145 passes... wow! I'd be willing to bet it got fractured when the inner let loose. Quote Link to comment Share on other sites More sharing options...
Zfan1 Posted August 25, 2014 Share Posted August 25, 2014 Manual transmissions are much harder on parts too. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted August 26, 2014 Author Share Posted August 26, 2014 Found problem-driver side axle is too short and the CV cage jumped out of the outer CV housing. Then the axle slammed the inner CV deeper into the case and bent it at the press fit of the stub to the CV housing, the stub pushed thru the CLSD carrier and kicked the passenger side axle part way out of the diff and trashed the oil seal. Weird that this setup held up for two years, although I did mess with the camber some, but I think I actually pushed the wheel in some, but I had just lowered the car which reduced spring pre-load...I dunno. I think all the planets were just in that majic spot to make a borderline situation manifest itself. One thing for sure is that the axles need to be tight enough to lengthen about 1/4" from full droop to full squat. So I now need to make the driver side 3/4" longer and the passenger side 1/2" longer. I have an extra set of CVs to make up a pair of axles and I have some stock shafts. Will mock up several options tomorrow night and see what I can come up with. A modified Z is never boring. At least I now know to mock up totally on the car with the CV boots pulled back. I thought I had all the lengths perfect, but I think the little jiggle of free play that I was feeling in the past was just the play between the inner CV and the snap ring that golds it into the diff. I fooled myself. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted August 27, 2014 Author Share Posted August 27, 2014 Swapped a short stock Z31 shaft in place of the passenger side M2 shortened shaft and swapped the long M2 shaft to the driver side and mock up without boots looks great. Time to tear down, grease, install boots and get it back together. These CV axles are easy to work with when they are clean and don't have 40 years sticking each piece together. Need to get to junk yard and pick up another set to have on standby. The splines are tighter on the stock CV axles than the custom shafts that accounts for a bit of my total driveline slack. Back to work so I can drive to work tomorrow. Daughter got a zero on band today cause I drove her jeep to school and got away with her sax in the trunk. Oops. Way to go Dad. Quote Link to comment Share on other sites More sharing options...
Eric JB Posted August 27, 2014 Share Posted August 27, 2014 I have a 72 521 truck, LZ 2.3 /stick, I bracket race. (13.60's @ 94mph) I cant run a 2 step in my class, so I had to find a way to leave on the high chip (7k) without it coming apart. This is what worked for me. Plumb a line lock between the clutch master and slave. (39.95 Summit). On each side of the line lock, put a T running to a one way adjustable valve. (28.00 McMaster Carr) Wire the line lock to a switch on the shifter so it is only activated when pushed in 1st gear. It diverts the fluid through the valve so you can control the flow and reduce the shock. Once you get it set you can lock it down with a locknut. Three years of abuse without a failure. Push the shifter forward, mat the pedal and let it go. Sorry for the thread jack. Just trying to help. My V8Z digested the stock halfshafts last week (auto) so I feel your pain. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.