chronic broken left front axle

[T.P.]

I was looking at a thread and Tytilidie described something I experienced three times, I was on the freeway with my wife at about 70 and out of nowhere CLUNK and the truck yanks hard to the left, luckily I was able too keep it off of the cement highway divider. That was 3 months ago.
limp it home, lift it, axle boot was split w grease all over.The shop I use said it was the axle. got it repaired, all was well. 4 days later, backing out of the driveway, CLUNK. Different parts breakage, this time was the yoke.
got it repaired two months go past w no problems, then going to the airport doing about 75 and CLUNK trunk yanks hard to the right, almost hit an old man in a caddy, but caught it before I touched his vehicle.limped it to the airport looked underneath, axle grease all over the left front wheel, again. Got it towed,front left axle again....got it repaired then painted. got it back 5 days ago. on the second day I got it back, on the freeway at 70 and CLUNK- same bloodclaat thing happens again. What is the solution to this? TC case Rebuild? Custom axles? Does Prime Gears have a strong replacement TC? Any help would be appreciated, as I am more of a driver than mechanic, please excuse any misnamed parts, but this is driving me nuts.

 

[WyoSyclone]

Re: chronic broken left front axle

What brand of parts are being used as replacements? If you take it back to the same place, they're probably just getting replacements under their warranty program and really don't care. NAPA usually has 'premium' grade options of most parts.... specify that you want a certain 'premium' part, then ask for the receipt so that you know what you got..... so many cheap friggin' chinese knockoff parts being produced these days.

 

[Josh Young]

Re: chronic broken left front axle

The previous owner of my syclone had a similar problem, I know he took it to the dealer and they thought there was trouble in the front differential. It turns out the problem was with different tires. The tires were the same size, but different brands. There was apparently just enough size difference between manufacturer's to cause a problem. Not sure if this is your problem, but just a thought. Good luck.:tup:

 

[JSM]

Re: chronic broken left front axle

Check the diff mounts.

Truck stock height or lowered?

 

[jwaller]

Re: chronic broken left front axle

all good suggestions so far but I'll throw out the idea of an issue with the front diff and or the pass side axle isnt engaging the splines in the diff.

this is very unusual and isn't normal. you have a problem and swapping the cv isnt it. you need to find the root cause of the issue.

 

[TYTILIDIE]

Re: chronic broken left front axle

Ill tell you what I came up with. I had a bad viscous coupler. I read and read and read, and not just about SYTY's, this apparently happened to several Safari/Astro owners as well. The answer is NOT in the CV's. Believe me, I went through 6 pairs:lol:, Carquest, NAPA, Pep Boys, Advanced Auto, Autozone, Checker:tup: I replaced the VC with a junk yard unit just in case that wasn't the problem. Well guess what, it worked!!! I wouldn't waste second, find a brand new VC and rebuild your transfer case. You can do this your self for around $600 with new VC, chain, bearings and seals. Good luck.

 

[Raist103]

Re: chronic broken left front axle

on my way out to the pittsburg meet i started getting a vibration and the first night there my drivers side cv broke. changed it there and on the way home lost the front diff completely. my guess is the front diff being bad causes the cv strain and it breaks. changed front diff and it has been all good since.

 

[George Blake]

Re: chronic broken left front axle

I believe there is something broken in the front diff. You are either catching a piece of broken cast iron in there or there is excessive play and it's not allowing the gears to mesh. Problem is that there is no telling what this has done to the transfer case. The viscous can absorb quite a bit but not that if it has been happening over and over again. Get a 4x4 s-10 with 3.42 ratio and swap your passenger side axle tube off of your housing and put that into your truck. Use the propshaft flange from your truck and put it on the donor diff.
What I think is happening is that the diff seizes up and the momentum of the truck continues to push the tire along the ground and just twists the cv axle off.
The cv you are using are most likely fine.
I can get you the front prop and a rebuild set to completely revamp the transfer case. I'd recommend the t-case being redone after what it's been through. That is a huge stress to put on the viscous as sun gear shaft that the viscous is on is suddenly stopping while the outside of the viscous is still being forced to spline by the output shaft. I'll be surprised if the viscous isn't popped and the planetary broken.

 

[TYTILIDIE]

Re: chronic broken left front axle

I believe there is something broken in the front diff. You are either catching a piece of broken cast iron in there or there is excessive play and it's not allowing the gears to mesh.

Exactly what I thought, $500 later with a rebuilt front diff and still snapped half shafts like slim jim's. If your front diff were bad like that you would know it. When mine really was bad you could hear it make treacherous sounds when turning, "on its way out" it would hum pretty loud on deceleration. If your shafts are just breaking with no pre vibration or any kind of warning, its safe to say you have the same problem I did.:2cents:

 

[T.P.]

Re: chronic broken left front axle

I'm leaning toward the Idea of a diff rebuild....definitely got vibration before this happened each time, and The diff hasnt been serviced since Ive had it, and given the state the rest of the truck was in was in when I got it, It's probably overdue. George, you said you could sell me a diff rebuild kit w/everything I need to get this sorted? Let me know how much, and since I intend to make at least 60% more power than stock, would like to build that part of the driveline accordingly.
Thanks ALL

 

[George Blake]

Re: chronic broken left front axle

I'm leaning toward the Idea of a diff rebuild....definitely got vibration before this happened each time, and The diff hasnt been serviced since Ive had it, and given the state the rest of the truck was in was in when I got it, It's probably overdue. George, you said you could sell me a diff rebuild kit w/everything I need to get this sorted? Let me know how much, and since I intend to make at least 60% more power than stock, would like to build that part of the driveline accordingly.
Thanks ALL

I don't do the parts for the differential. I'm afraid what your gonna find is that the front diff was empty of fluid. I do the transmission,transfercase, driveshaft components. I'm covered up with that. ANYTHING you need in the trans or T-case or propshaft type gear, I can take care of.

http://www.lmctruck.com/ICATALOG/CST/full.aspx?Page=149

Look this over and see what all is involved. I'd recommend getting a good donor front diff and going through it. If you want, I can scan the Helms docs and link them so you can see how they recommend getting the sub assembly apart. I'm pretty sure that's in there.
Don't do the front locker. Now someone on here that might be able to help you on the front diff is Mike Hood. I almost forgot about Mike. Give him a looksee. tuckerauto is the business and the screen name is sytyguy.