Broken Axle & I Do Not Want to Do This Again

SierraHawk · 11-29-2017, 12:14 AM

Labor will be about $1000. Axle is $500. I do not want to do this again in the future.

2003 SMB 4X4. Got tired of rebuilding the rear differential stock LSD every 60,000mi. Installed full float differential with Eaton Truetrac and new axles 4 years ago/76,000 miles approx. Went for a drive on a moderate FWD road in the Sierras. Did the entire 8 mile Buttermilk loop in low gear and, because of the rocks that emerged in this spring runoff, I went slow. No tire hop or any extreme use. I am 67, have been traveling full time for 10 years and tow a 1976 29' Airstream about 30,000 miles a year.

Got to town and stopped to visit with mom. An hour later I slowly backed out of her drive. The van started to make some serious noise. When I put it into park it rolled forward into a fence and stopped. Got out and looked for any signs of damage but everything underneath looked good and no oil on the ground. Tried to back up but the van did not move. Some noise but not as loud.

Put the rear axle shifter in N and put the front axle in L and drove to town. No noise from the rear diff in the 5 miles I drove. Called trans guy. Drove to the shop. Mechanic pulled the diff cover off and saw that the left axle shaft had broken at the spline. Needed a magnet to get the stub out of the carrier. Most of the stub came out but there is still another part of the axle inside of the carrier.

This is a strange kind of break. Splines are good. The end that attached to the non spline part of the shaft is broken but there are several small cracks that radiate out from the center of the shaft. There is a piece of the spline end that is still in the carrier.

Why would the axle break in two places? Both breaks are through the spline section of the shaft and the splines look OK. Why are there several small cracks that radiate out from the center of the shaft?

All shafts are on back order. Only shop that has what I need is a Ford dealer in Chicago. Any sources for axles that are within 500 miles of Bishop, California? (near Yosemite and Mammoth Mtn)

JoeH · 11-29-2017, 12:19 AM

Unless you swapped out the full float D60 has 32 spline axles. If there's other damage in there you might consider swapping to 35 spline.

carringb · 11-29-2017, 07:50 AM

Do you have a pic by chance? Your descriptions makes me suspicious of a metallurgy defect, not a fatigue or overloading.

JoeH · 11-29-2017, 01:15 PM

Just to confirm, we are talking about a full float right and not a semi-float rear axle?

You can source the axles from Yukon or Dutchman for considerably less than $500.

SierraHawk · 12-04-2017, 09:26 PM

Yes it is a full floater. All of the parts shops that carry this particular axle are telling me that they are backordered. Must have been a great summer for exploring the great outdoors. The only source is Ford in Chicago.

They shipped the wrong axle on Monday. Go figure. Promised the correct axle would be here on Wednesday.

We tow a 1976 Airstream we renovated. Fortunately we had parked it in town but it is costing $40 a day.

I went back to the shop and took some photos. I never liked the upload feature on this forum but they may have made it a bit easier in the past several years. When I figure out how to post them I will do it in the morning. Thanks for the information and questions.

I am not sure the fine cracks that radiate from the center of the shaft will be visible but it will be worth the effort if the photos are crisp enough.

MadScience · 12-04-2017, 10:13 PM

I'm also surprised that there are no aftermarket replacements to be had.

Which full float do you have? Based on the lack of aftermarket, I'm guessing a D60 for a van?

I presume you understand the torque multiplication in low range. In addition to that, a locker can put all the torque you have through a single axle.

JoeH · 12-04-2017, 10:31 PM

Well, there are. https://eastcoastgearsupply.com/c-27...le-shafts.html

Axle Shafts | Performance Axles - West Coast Differentials

Nobody has anything in stock?

TheJoeSmith · 12-05-2017, 08:38 PM

Did you find the axle? Were you able to get it fixed?

SierraHawk · 12-06-2017, 03:29 PM

We are still in Bishop, CA. The shop ordered 3 axles and none fit. Finally got the number for the Yukon axle that broke. Apparently they cut the splines long (too long in this case) so that they can be fit into multiple axles. Told that a break like this is typical of Yukon axles. One end has a few leaf parts because I was more interested in getting the photos and forgot to clean it up.

I think the groves around the splines that are so prominent are from the long end of the axle hitting the short part. You can see the lines that radiate out from the center in the third photo. I was told that the shop will order an axle from Ford. Can't wait for the other side to crumble.

TheLetterJ · 12-06-2017, 06:04 PM

This may be a silly question, but seeing that you already have non-OEM shafts in your axle, do you also have a non-OEM spline count? What diff do you have in there, i.e.: detroit, ARB, true trac, etc?

Factory Ford shafts in a D60FF would have been 32 spline, and I believe that Yukon only makes 30 and 35 spline D60 shafts, in other words, the Ford axles that you ordered may not fit.

I'd urge you to get a good count ASAP before going any further. If they turn out to be 35 spline, skip the cut-to-fit shafts and call Dutchman for some proper length shafts. 1541H (slightly stronger than factory) shafts cost about $350 shipped, 4130 (much stronger than factory) were about $400 a pair. I had a pair made to order, in my hands in just a few days.