Front shaft clip?

[nxp]

Hi everybody.

I've changed the front right bearing on my Mazda 121 a week ago and most of the time it seems to be working fine.

BUT

I must have pulled the shaft out while I had the hub dismantled (had to struggle to get it open and disconnected). I am sure I pushed it in back quite hard and the splines had engaged and I felt a thunk as if the shft had clipped in place. The problem is that in normal driving the shaft simply seems to slide out from its place leaving the diff to spin freely - once it's happened only a minute away from home and another time in a choke-point of a busy intersection (not the nicest place to try and fix it). Anyway, both times me and my bro managed to push it back in place (with the car jacked up) and move on.

So, my questions are:

Do any of you know what kind of clip hold the front shafts inside the diff? Any idea how to remove/replace it and if any special tools are needed? Is this a part which you can find easily at any spares shop and what do I ask for?

On a completely different topic, what are these shims I keep hearing about when you replace front wheel bearings? I did not find anything that even looked like a shim, and I changed nothing except the bearings themselves and the oil seals. There was something like a very thick washer, some 4mm between the inner and outer bearings, is it that and are there any problems if I reused the old one???

Thanks for everything
NxP

[jglutz]

1st: a 'cir-clip" holds the spline into the differential. The clip only holds the the spline into the diff case during assembly so they don't fall out. The shafts are normally pulled out with a switft tug. They are not strong enough to handle normal driving/turn forces. Also, the lower conttrol arm and strut prevent the wheel assembly from becoming further away from the diff case. As the wheel moves up & down or pivots for turning. and change in shaft length is compensated for in the tripods (a bearing/spine assembly) located in the metal cup at the differential. If the shaft/spline beame detached from the diff case, you would loose alot of ATF. Something else is wrong. Either in the tripod or the transmission. My guess/sugestion...pull the shafts out, remove the inner boots and check that the tripods are functioning properly.

2nd...the shims you refer to: When the new front wheel bearings are insalled, a spacer is (re)palced between the the inner and outer beraing. Once the bearings are installed, a bench/torque test is done to turn the wheel. If to much torque is required to turn the wheel assembly, shims are added to the spacer to reduce the amount of bearing preload. If quality bearings where properly installed (everything clean and seated), their is a very unlikely chance shims are required. The spacer was factory selected to compensate for diferences in the machining/assembly of the castings. If the bearings where not properly installed, it won't take long to find out.

I haven't checked the Hanyes manual but the Ford factory manual is explicit. Let me know and I will send picts.

Good Luck!

[F3BZ]

i was unaware of any shims being added to the spacer to achieve the desired preload turning torque. my manuals list a selection of 21 different spacer thicknesses to acheive the desired 2.2-10.4 lb-in turning torque.

[FB71]

you're correct F3BZ, the spacers are replaced, not shimmed.

[gdawgs]

i was unaware of any shims being added to the spacer to achieve the desired preload turning torque. my manuals list a selection of 21 different spacer thicknesses to acheive the desired 2.2-10.4 lb-in turning torque.

This would be the correct way to do it if the preload were off. However, you cannot get these spacers anywhere. So if you need to adjust, you either have to make a shim if the preload is too high, or machine off a bit of the existing spacer if the preload is too little.

[F3BZ]

most of the spacers are still available but not from ford. of the 4 bearing jobs i've done on various festys, all of the existing spacers that popped out were #12, the middle range. rather than spend a night at the vise with an lb-in torque wrench, a spacer selection tool kit and a stack of spacers i just threw back in the #12 spacers and pressed everything back together. i checked for any play or tightness by hand and reinstalled the knuckle. good to go for another few years. i'm not a machinist but it seems overkill to search for a spacer that is one 16th of a 1000th inch bigger or smaller when the acceptable turning torque spec goes from 2.2 all the way to 10.4 lb-in.

[FB71]

I agree. I've done three sets of front bearings, all six spacers were #12s, and all six turning torques were in spec after installing the new bearings (I have the special service tools).

[jglutz]

Yes, the factory manual does list numbered spacers. When I purchased inner seals, the illustrated parts list mentioned the use of additioanl shims kits rather than purchasing spacers.