I am trying to change my front flex disc which I have unbolted. I am having problems removing the front axle to take the old one off and replace. I have removed the heat shield and see the 46mm nut. If I manage to loosen it how does the shaft come off. I have dropped my exhaust system but removal due to rust is impossible without creating other problems. Is there a way around this - I cannot slide shaft back enough to drop the front off the tranny so I can replace the disc. Any help would be appreciated.

I lowered the tranny and without loosening the big nut at the rear end of the front driveshaft I was able to slide it back about an inch or two but the shaft wont quite disengage from the tranny. Is there anybody thats replaced the front driveshaft on a 1989 300se that has some insight? I can see that theres a centering pin between the driveshaft and the tranny from the repair manual which is pretty vague. Tommorrow I will cut the old flex disc off and see if that pin is floating - unless somebody else has a better idea.

You need to use a pry bar and wedge it between the flange and work it loose.

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1990 190E 3.0L

agarn, best to use a 46mm open end wrench to loosen the driveshaft clamp nut. Although I'm unfamiliar with your 300SE driveshaft, loosening the nut should allow the driveshaft to slide further so you're able to remove the flex disc. If you haven't done so already, be sure to match-mark the driveshaft sections and the transmission so it reassembles as-is.

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Fred Hoelzle

I will try the crowbar method first. If not I have to order a 46mm wrench. With the exhaust dropped but not removed it would still be hard to turn the nut. I would have to cut the bolts at the exhaust manifold and I dont see how I could remove the studs and retap without taking the head off. The manifold to head bolts are also rusted beyond recognition. A simple method would be to sawzall the exhaust pipe at a convenient location and reconnect with a union and clamps but I hate to hack my car up. I'll report on my progress. Thanks for the input.

You can use a pipe wrench to turn the bolt. Jack up both rear wheels, adjust pipe wrench to fit snug, release parking brake and shift the car to neutral, rotate drive shaft with wrench attached all the way to the opposite side you will be turning to loosen, put car back in park, engage the parking brake and then go turn the wrench. Repeat that process until the nut is loose. It sounds like a lot, but it only took me a total of 20 mins, from jacking car up and putting it back on the ground. I only had to remove my exhaust heat shield and loosen the nut a bit (I replaced my center bearing/support and tightened it back up but them realized a few days later that the drive shaft should be able to telescope, I had the nut too tight.)

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1990 190E 3.0L

I did manage to pull the shaft back enough without turning the nut and in conjunction with lowering the tranny I was barely able to get the shaft off and on. I only have to put it back together today. A word to anyone who buys the flex disc from uro parts - the supplied nuts are too hard to thread on the supplied bolts. After struggling with the hardware I took a nut, put it in the vice, and I needed a large breaker bar and I barely had enough strength to thread it on. I know how tight these are supposed to be but these are definitely out of spec. I'm going to buy new nuts of the same type and use loctite. Thanks to everyone for all the input.

Several members will caution against using uro parts as they say they are cheaply made. I personally have a uro parts flex disc on my car and I posted about 2 years ago that I was installing it. 2 years later I made a repost to inform members that the part has several thousands miles on it and does not show any sign of wear.

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1990 190E 3.0L

This is one of three cars I drive so I do go for the cheapest parts. The reality is that I drive this car 5000 miles a year and that flex disc will last for the remaining life of the car. I finished the repair and still have a slight vibration from 65-75mph so I am going to replace the tranny mount next and cross my fingers. I did the motor mounts last year so if its not that its probably that u-joint between the axles - I definitely wont mess with that unless it gets worse.
Thanks for the help.