1991 300SL Flex Plate

[sldan]

I will be taking my 1991 300SL into the dealer soon for it spring oil change.

I will also have the drive shaft front and rear flex plates inspected.

Due to the 57,400 miles and the age on these rubber componets I am considering having them replaces regardless of the condition.

I am wondering what to expect for the cost of repair.

Has anyone replaced these components or have any comments?

sldan

[Chamorro]

I'm going to guess about 1 hour of labor + $150 for the parts.

[bobterry99]

Dan, unless they don't pass inspection, I'd leave the flex couplings alone. There are plenty of other parts on your car that are going to wear-out long before these. If you want to throw money at your car, you might consider replacing them first!

[sldan]

Hi Bob,

Thank you for the reply. I will have them inspected and see what they look like.

What is your thoughts on replacing the flexible brake hoses?

I thought about changing the flex plates because of the following service bulletin I found on AllDYI:

Flex Disc - (Torsion Style) on Front Driveshaft Improved

TO: OUR MERCEDES-BENZ PASSENGER CAR DEALERS

Date: July 1992 (supersedes S.I. 40/130, February 1994)

Ref. No. MBNA 41/1c

Revision: 100 and 110 mm flex disc included.

SUBJECT:
ALL MODELS - INSTALLING LIMITED TORSION FLEX DISC ON FRONT DRIVESHAFT




The flex discs, particularly the front flex disc (transmission-side), may be subject to very high dynamic and thermal loads depending on driving style. Therefore, the flex discs (front and rear) must be inspected every 30,000 miles on all models as a part of routine maintenance. Damaged or cracked flex discs must be replaced.

[tecqboy]

I had both discs replaced on my 1991 300SL last summer at around 95K miles. The front disc had very small hairline visible fractures. The rear disc looked perfect. The total cost of the job at a local MB independent shop was $370. I can't find my original receipt sheet with the breakdown of parts vs labor, but I remember it was 3 hours at $75 per, so the parts must have been about $130 plus taxes. Your mileage is much lower than mine, but the vehicles are the same age. The discs are not difficult to inspect on your own. Just jack the car up a bit and have a look. Wipe them off with a rag, get a brite light and look for signs of fatigue. BTW, I had no vibrations from the drive shaft. I had it done because I noticed the cracks while changing the oil.

[bobterry99]

Dan, unless the brake hoses show signs of deterioration, I'd leave those alone too. As far as I can tell, my '69 SL still has its original hoses.