Hey all,

I have my flex discs and trans mount in hand to put in this weekend. The trans mount is old and suspect, and the the flex discs are cracked.

But, how do I tell if the center mount is OK? Im going to be in there anyways...

I do not have any objectionable vibration. This would be pure PM.

Any good test methods to consider? Amount of play when pushing? Something else?

Usually Id be all for some extra PM but I really want to not do lots extra here - this is pretty much the last major item before my car is my daily driver after 9 months of adventure

Thanks,
dd

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

I would examine the amount of up/down play in the mount while it is still installed. It should be very slight- maybe .5". When you have it out check for roughness/play in the bearing and see if the rubber is deteriorating.

I PMd all my flex discs ,center supports and bearings on my cars just on general principle. I don't expect to ever have to look at them again. You can get the mount and the bearing together for about $20, IIRC. Once you have the driveshaft off the car, it takes maybe 15 minutes to change it.

Rick

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80 300SD (129k mi) 82 240D stick (193k mi)77 240D auto - stick to be (153k mi) 85 380SL (145k mi) 89 BMW 535i 82 Diesel Rabbit Pickup (374k mi) 91 Jetta IDI Diesel (155k mi) 81 VW Rabbit Convertible Diesel 70 Triumph Spitfire Mk III (63kmi)66 Triumph TR4a IRS (90k mi)67 Ford F-100 (??)

I'm thinking it may just be time to replace the center driveshaft bearing, transmission mount, and differential mount on my 84. They're all suspects in the vibration and noise I'm hearing under hard acceleration, all of unknown age and condition.

If there's a good way to test all of the driveline 'perishables' without removing them, I'd be interested to know as well.

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1983 300SD 467,000 km - 473 champagnermetallic

location: 34°5' N 106°53' W (Socorro NM, USA)

If you are replacing the flex discs, I would replace the center mount and bearing while the driveshaft is off the car. Do it once and be done with it.

Tango,

If I am seeing things correctly, I do not have to take the driveshaft off to change my flex discs. But I certainly do have to take it off to get at the center support /bearing.

How much more time is it to fully remove the driveshaft and re-install?

dd

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

You are going to need to "drop" the center support (two bolts) in order to move the shaft forward to r/r the rear flex disc, so it's not really a lot more work to replace the mount and bearing. Although you will need to disconnect the parking brake cable in order to completely remove the d/s.

If you decide to replace the center mount, make sure to match mark the front/rear drive shaft segments so that you can put it back together the same way. Same for the flex discs ends.

once you have the flex discs off, there are only the 2x 13mm bolts that hang the driveshaft at the center support to take off.

If you do decide to change the rubber center mount pay attention to its orientation. It is a good idea to mark the front of your old one and then match up the new one so that it faces the same way.

Edit- Yes, also mark your driveshaft halves. I did not remove my brake cables- just slid the driveshaft over it.

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80 300SD (129k mi) 82 240D stick (193k mi)77 240D auto - stick to be (153k mi) 85 380SL (145k mi) 89 BMW 535i 82 Diesel Rabbit Pickup (374k mi) 91 Jetta IDI Diesel (155k mi) 81 VW Rabbit Convertible Diesel 70 Triumph Spitfire Mk III (63kmi)66 Triumph TR4a IRS (90k mi)67 Ford F-100 (??)

Thanks for the replies guys. Looks like Ill take the shotgun to this repair as well...why the heck not at this point :-) Its worth a few hours and 70 bucks to know that I wont have to mess with it again.

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

Center bearing and bushing should be about $35 from ********az.

You will need something to drive the bearing down over the ds. I found a piece of 2" or so pipe from my old fence worked just fine.

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http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

Alright, in hopefully a final large PM project for a while my driveshaft comes out tomorrow.

Ill be back with questions...Im sure lots of them

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

dont have wrenches big enough to take off the center driveshaft sleeve nut. looks like its on to another project for today.

what do other folks use to do this?? who stocks wrenches this big? i called autozone and they didnt have anything that big to buy/rent. I tried some big channel locks but they were too thick. doh!

dd

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

You just need to loosen the "big nut", A LARGE set of channel locks worked for me.

I didn't have to mess with the brake cable either.

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

stevo,

just one channel lock? how did you hold the driveshaft? judt unscrew it in P so you were turning against the engine?

dd

__________________
-------------------------------
'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

Any way too hold the drive shaft works, just be sure too jack up one rear wheel (or better yet, both) when your ready too work on the flex discs. I use an impact wrench,
and be ready with a big screw driver/pry bar too free the disc from the flange.

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

I used a large, cheap adjustable (Crescent type) wrench.