blown 944

This^

I have also looked into another reason the axle cages break after many miles and I have come to the conclusion that the cage and ball wear gets to the point where the ***** extend past the cage enough to become dis-engaged.

I found this when I heard the axle hitting the outer hub. I am working on a delrin plug that will limit the total lateral travel of the axle shaft so it will remain in the optimum position even when worn.

lejams

The cage on my CV hasn't broken in fact it looks to be in pretty good condition. Although in time it may have if I hadn't caught it now. But had it gone onto break, it would have been for the lack of lubrication, and not just typical wear. At 95k I don't have any evidence that there was any excessive side way movement. The end of the axles are unscathed and the wheel hub still has grease in it nice and smooth. The picture is from the CV joint next to the TA. No way the axle could hit in the TA hub because its more funnel shaped and way to deep.

lejams

No offense but there is some conjecture here. All things being relatively equal on both sides of the TA, how do you establish everything always twists in a certain way? How do you know that the movements are always the same and how is it known that it always puts more stress on only the driver’s side? For all practical purposes, my TA mount looked as good as new. After I cleaned it up good, I could not find any cracks or striations of any kind. This is my point.

lejams

Regarding cages breaking, there are some known issues with breakage sometimes when people buy a kit and rebuild themselves. Bill & I discussed this and the importance of re-assembling the cages correctly when repairing the joint. Although it’s relatively simple, there is a way the Cross Grooved Joints are to be reassembled that can be overlooked. Because Cross Grooved Joints are cut at an angle, unlike a Double Offset CV Joint which the grooves are cut perpendicular, (or parallel with the axel bar), the orientation of the Outer Housing to the Inner Race must be correct. If not, the cage will definitely break. Attached is a PDF specifying how to re-assemble the joint.

95ONE

Because it does. centrifugal forces, velocity vectors and all those fancy things taking into account rotational and transversal pulls on the transmission when considering the torque from the motor twisting the whole assembly and the "pull" of the axles. Assuming this is happening when accelerating forward and not going in reverse. How exact would you like me to be in explaining this? Same angle and direction of deflection relative to intensity using stock mounting points and tolerance that gets looser with age on both ends. Damage varies with intensity depending on drivers right foot and, well, left foot too, hence your nice looking cages. Things are not equal on both sides of the TA.

lejams

95ONE - Thanks for explaining, guess I should have been clearer. I was looking for something more tangible.

lejams

I know that engines and trans-axles shift, (within the tolerance of design). Was just trying to find out, in this case, what is causing things to wear more in one direction than the other. This was designed by Porsche to move laterally. Given that is happening within the designed tolerances, was really trying to find out what if any other parts are wearing and contributing.

acorad

Sounds pretty tangible to me.

lejams

Using a digital bath scale, both the original oem & EMPI weigh about the same, i.e. 13lbs.

V2Rocket

So who'll be the first to machine up some titanium axles

bouldersyncro

Great thread!

I found this thread searching for information about installing 944 axles onto a Vanagon and thought I would throw in my $.02.

Just to be clear, Vanagon axles are 21.25 (540mm) inches long. I think that lejams meant that the 944 axles measured 21 1/8, not 24 1/8.

Anyway, some of us in the 4WD Vanagon Syncro world have lifted our vans for better off road performance and are looking for a CV joint with a greater “Maximum Angularity”. The internet reports that the type 2 CV’s on a Syncro are rated at 17*, whereas the type 4 CV’s on the 944 are rated at 22*.

Thanks to lejams we now know that EMPI claims no variation in maximum angularity exist between the different types of CV’s. However, I replaced one of my stock Syncro axles with the EMPI 90-6805 and noticed that my maximum suspension droop (before the CV starts binding) increased by over an inch with the EMPI axle. So apparently there is some difference in maximum angularity, just maybe not with EMPI CV’s. The EMPI axle also measured 2-3mm thicker than the original Syncro axle. This all seems like good news for those of you running EMPI Vanagon axles on a 944, as they seem to offer a thicker (stronger?) shaft and greater maximum angularity than the original Vanagon shaft.

However the general wisdom of the Syncro community is that EMPI axles and CV’s are not to be trusted off road and are breaking at a significantly higher rate than the OE (GKN/Lobro) axles. These failures are in off road conditions, many times with one wheel off the ground and diff locks engaged and not while on a track (ha!) or daily driving. Being that AAA does not come get me if I break an axle up some Jeep trail I have just bought a pair of new Lobro 944 axles for my Syncro. Ironically new GKN Syncro axles are not available. Once they arrive I’ll compare them to the EMPI and OE Syncro axles and report back.

dmcampbell

I found correct part on Parts Geek. Any track use updates on these axles? I need new ones and would rather swap than rebuild. Thanks, Mike

pontifex4

Great first post, and welcome!

lejams

Thanks for correcting my error on the axle length. You are correct and it should have read 21-1/8”.

Interesting about your findings on the differences between the EMPI & GKN/Lobro’s. You may find it beneficial to talk with Bill @ EMPI sometime. Apparently, although the SAE standard on all Cross Grooved Joints as Bill read from the book, is a maximum angularity of 25 degrees. Maybe globally not all manufactures comply for one reason or another? I don’t know under what circumstances, if or how, SAE standards interact globally, but in accordance with your finding, sounds like there can be differences.

I don’t have many miles on the EMPI’s yet, but so far so good. However, even though your use is off-roading, which probably neither manufacture intended to warrant, I’m a little disappointed to hear that the EMPI’s are not meeting some of the same stresses as the Lobro’s.

Reimu

How are you guys bracing the trans?