# Rebuild a driveshaft in a 3 series (universal joint DIY)



## 323ci_bimmer (Sep 1, 2008)

I thought I’d write this DIY because I was unable to find a DIY anywhere on the internet on how to change a 3 Series E46 Staked in Universal Joint. 
IT IS POSSIBLE, it just takes a bit of time and patience.
If you’re not experienced at working on vehicles DO NOT ATTEMPT THIS DIY. I have a lot of experience with cars including rebuilding a Porsche Boxster Engine (not as impossible as the internet would have you think) and I can tell you changing these Universal Joints are frustrating. Also, just because your car is vibrating don’t assume your u-joints are worn out. My rear u-joint had a lot of play and WAS actually worn out (the needle bearings had came right out) but my car has almost a ½ million kilometers on it.
First the parts (I choose to rebuild my entire drive shaft):
-2 Neapco Universal Joints P/N 1-0431 (I bought them from Drivetrain America for $16.39 each)
-1 BMW driveshaft flex disk (P/N 26111227410 for a manual transmission)
-1 driveshaft center bearing (unsure of P/N but I recommend you buy one with the mount included)
-6 Flex disk hex bolts (can’t re-use old ones) (P/N 26117523709)
-1 PB Weld kit (found at any hardware store)
The parts cost me a total of $115.95 USD
Second the tools:
-You’ll have to figure out the ratchets and sockets yourself.
-1 dremel tool aggressive enough to grind the stakes out of the driveshaft
-1 standard grinder with a metal cutting wheel
-1 reciprocating saw with metal blade
-1 vice
-1 big hammer
-1 magnetic base with a deflection gauge (also sometimes called an “endplay gauge” found at any machine shop supplier). I found mine at Prince Auto.
-1 punch approximately .90 inches across
-one micrometer that can measure inner and outer areas of the driveshaft ears

There are some things I’m not going to walk you through step by step because if you can’t figure out exactly how to take off your exhaust system you shouldn’t do this job.

Start:
If you have access to a lift your ahead of the game, if you’re like me and your garage is full and you don’t have a lift then I recommend you park your car in a clean piece of your driveway and jack up the entire passenger side high enough that you can comfortably lay under your drive shaft. I used 2 jack stands and a bunch of ends of 2x8 to do this.
Remove the exhaust system and heat shields from behind the catalytic converters back. My car has 426000 kilometers on it so this included very rusted nuts and bolts. 
I was unable to get the nuts off at the rear of the catalytic converter so I had to grind them off and drill out the old bolts. They become VERY hard over the years from heating and cooling over and over so this in itself is almost as time consuming as the rest of the job.
I also had to cut the right pipe 3 inches past the flange because I couldn’t get a grinder into the top nut on the flange. With the exhaust system out of the way I could get the last nut, this meant I had to get a $5 repair pipe and weld it in at the end. You could also just use U clamps for the repair pipe if you don’t have access to a welder.
Now that the exhaust system and heat shields are off, remove the driveshaft tether. It’s not a traditional tether, its just a piece of aluminum that goes across under the rear of the drive shaft so if it breaks it won’t fall out on the ground. The tether is bolted as part of your rear carrier for your rear-end. I didn’t have to support my rear carrier but you might. As you loosen the bolts for the tether, watch the carrier to make sure it doesn’t drop too far. 
Activate your emergency brake as hard as you can. Loosen the reverse torx bolts on the rear of the drive shaft (drive shaft to rear end) but don’t remove them. You will need to release the brake and turn the shaft a couple of times to access each bolt. Now loosen all 6 hex bolts at the front of the drive shaft (drive shaft to transmission). 
Loosen the central nut connecting the rear and front driveshaft sections just behind the center bearing. 
Now you can remove all the driveshaft bolts (front and rear). Remove the center bearing nuts. The driveshaft can now be moved around a bit and completely removed from the vehicle. Separate the front and rear driveshaft. Remove the C clip and drive the center bearing of the front shaft off.
Now the fun part!!
Using a dremel tool or a drill press with a dremel bit in it grind the stakes out of the inside of the ears on the driveshaft that are holding the universal joints in.
Using a hammer and a punch hammer out the old universal joints (this takes a lot of force). MAKE SURE YOU SUPPORT THE DRIVESHAFT EARS PROPERLY SO YOU DON’T BEND THEM!!! There are a ton of ways to remove universal joints, check out youtube. Using a vice and a couple of sockets works well also, just look it up.
---- Now a little theory ------
On the NEAPCO u-joint the center clips measure 1.900 inches from outer clip to outer clip. 
In theory, if you could cut each inner ear of your driveshaft smooth and perfectly equally leaving exactly 1.900 inches space between each ear you could then install the new u-joint and it would be centered. I don’t own a machine shop so I had to do my best.
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Now that your old universal joints are out you will see that the driveshaft ears are angled. This is what stops you from easily installing a serviceable u-joint. BMW was smart in making it like this because it means you have to replace the entire driveshaft when the universal joints wear out at a BIG profit to them!!!
I tried a BUNCH of methods to grind the inner ears smooth but NOTHING worked the way I wanted it. The proper way to do this is to take your driveshaft to a machine shop and have them machine out the inside of the ears to fit the new clipped u-joints. My car has a PILE of kilometers on it though and I didn’t want to spend a couple hundred dollars for a machine shop to do this. 
I first tried putting my dremel bit in a press and grinding out the inside of the ear to where I wanted it but there’s not enough room inside the ear to do this. I then tried using a miter saw with a grinding blade to grind the inside of the ears but the blade wasn’t firm enough and just followed the angle of the ears.
SO…… I using a micrometer and a sharp center punch and measured 1.900 inches in the center of the ear area and mark it with my punch by scratching the drive shaft ears. Do this on each side of the drive shaft ears.
Now use a grinder with a cutting wheel and grind the inner ears as smooth as possible leaving a little more then 1.900 inches on the inside of the ears so the clips can be pressed onto the u-joints with a little play (unless of course you have super human abilities and can grind exactly 1.900 inches out of the centre of the ears and have perfect equal thicknesses of ears left *impossible without a machine shop*.
Now install the new u-joints in the drive shaft. Using a vice try to get the universal joint as centered as possible in the driveshaft. Install the new center bearing on the front shaft and install the front section of the drive shaft without the rear section of the drive shaft. Use a Haynes manual to get Torq Specs for all bolts. I believe my front hex bolts were tightened to 74 ft/lbs. 
Now install your magnetic base and deflection gauge onto the bottom of the car and mount so the deflection gauge is as close as possible to the universal joint but measuring the deflection of the installed driveshaft.
----- A little rant ------
I read a LOT of forums about changing these u-joints and every one of them talked about having to “balance” a driveshaft after installing a Staked in Universal Joint and that’s why it’s impossible to do it yourself. I think the BIG misunderstanding here is the word “balance”. It’s a little misleading in this situation. The process isn’t actually ‘balancing’ the driveshaft, its ‘centering’ the driveshaft/u-joint. When you install the new u-joint it HAS TO BE PERFECTLY CENTERED in the driveshaft. If it is perfectly centered then the driveshaft will be balanced and not vibrate. If the driveshaft is installed in your car (and the rear transmission bearing is fine, the center bearing is fine and the input bearing on the rear end is fine) then a deflection gauge will help you center your u-joint.
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Now turn the driveshaft so the deflection gauge is measuring the deflection at the grease fitting side of the u-joint. Zero your deflection gauge. Turn the drive shaft 180 degrees at the transmission side in front of the flex disk. The centre bearing is mounted in rubber and it will mess up your measurements if you turn the driveshaft manually at the driveshaft. You have to turn the driveshaft without putting pressure on centre bearing rubber mount. 
Now, measure the difference in deflection between the grease fitting side and the 180 degree side. Use a hammer and a punch and continue to tap the bearing cap of the u-joint on each side until the deflection gauge is as close to “0” on each side as you can manage. You must tap the bearing caps and not the shaft. If you tap the shaft you will loosen the pressure on the u-joint and that’s not what you want. REMEMBER, the closer to ‘0’ you can get it the smoother your car is going to be. If you can get it within 0.003 of an inch at each 180 degree measurement your car will be SMOOTH. I could only get to 0.002 of an inch deflection and my car is as smooth as when it was new.
Now rotate the shaft 90 degrees from the grease fitting and do the same again. Once you get these two caps centered rotate the shaft 360 degrees and ensure that the deflection is still within 0.003 of an inch at each 180 degree point. Don’t worry if it doesn’t stay zero’d at every 90 degree point (your shaft is not perfect). As long as the gauge ‘0’ at the grease fitting then at 180 degrees, and is then equal deflection again at the remaining two caps your good (it may not be at ‘0’ on your remaining to caps. Mine was 0.01 off at my remaining two caps however it was equally 0.01 on the gauge on each remaining cap so that’s what counts. CONFUSED YET?!?!?! It’s hard to explain but easy to do.
Now when you look inside the ears of the driveshaft you will see that the clips on your u-joints have play (space between the clip and the driveshaft ear). You must take up that play otherwise the u-joint can move over time and bring your shaft back out of balance. I simply mixed some JB weld and pressed it by finger in between the clip and the inner ear all the way around on every u-joint clip.
Allow the JB weld to set (24 hours).
Install the rear driveshaft section between the centre bearing and rear end. Torq the rear bolts at the driveshaft and rear end.
Repeat the entire “deflection gauge” process. Once you get it as close to ‘0’ as possible repeat the JB weld process. Allow to dry to 24 hours. Grease the u-joints.
Grab the heat shield and side cutters and cut out 2 windows which will allow you to access the grease fittings with the heat shield installed again.
I also cut a “V” in the aluminum tether to make it easier to access the rear u-joint in the future. 
Re-install the drive shaft tether. Re-install the exhaust system.
YOU’RE DONE!!!!!! Test-drive the car and ensure it’s smooth. If you followed the directions the car will be smooth. Remember that if you installed grease fitted u-joints you should grease them every 10,000 kilometers or so. I grease them at every oil change personally (12,000km). 
Just a thought…… I don’t know if this would work or not but I thought about getting a staked-in U-joint for this car (just find a staked in joint with the same measurements as the NEAPCO 1-0431 joint). If I had done this I would have been able to not grind out the driveshaft. In theory I could have then spot welded stakes back into the drive shaft after ‘balancing’ the u-joint (perhaps with a mig welder and flux core). As long as the heat of the spot weld doesn’t damage the new u-joint this would allow you to basically have a staked in u-joint without the price of sending it away. ……. Just a thought……..


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