ring gear damage - attn Koan

[zeppelinboy]

So I am 99% sure thay my ring gear has a dead spot. Starter spins with a grind and doesn't start the motor, but if you turn the motor a little by hand, it catches.

I need to pull the starter to confirm the deadspot, but I am sure that is the cause.

Koan - you posted some time back about reclocking the flywheel in this post:

http://forum.w116.org/mechanicals/6-9-flywheelstarter-%27ring%27-and-front-pulley-nut/

At the end of post you mentioned that in the M100 manual there is a section on ring gear damage. I cannot find this section in the online library. Can you please point me in the correct direction, or if it is unavailable in the online manual, would you be willing to scan this section of the manual for me?

I would just use a new ring gear, but I can't find one, and I really don't want to spend 8 hrs in the junkyard pulling a a transmission in the dirt just to get a ring gear (that is if they even have a 450sel in the yard).

Thanks!

Justin

[koan]

So I am 99% sure thay my ring gear has a dead spot. Starter spins with a grind and doesn't start the motor, but if you turn the motor a little by hand, it catches.

That sound like the ring gear if you rotate the engine a bit and it works.

You might be able to rotate the driven plate and flywheel 45 degrees and provided the engine always stops at the right place it should work... a bit annoying if it doesn't though.

You could price one from a dealer, occasionally a part is lower than expected, suppose it depends what price you put on "8 hrs in the junkyard pulling a a transmission in the dirt"

I can scan the page of the m100 manual but all it says is:

Note:

Drive ring with welded on ring gear is balanced.

In the event of damage to ring gear by starting when engine is about to stop, Install an ignition stater switch 116 462 00 93 with larger repeat angle (series since 1978). As a result, during repeated starting, the ignition switch must be turned back to "0" ("1" before), which may cause crankshaft to come to a stop.

(the 6.9 ring gear is welded to flange and flange bolted to driveplate/converter, looks like the 4.5 ring gear is heated and shrunk on)

koan

[WGB]

Last year I was in contact with the fellow from South America who had the 6.9 which had been converted from hydraulics to springs.

He had the same problem and contacted me saying that M-B had quoted him US$1200 for new ring gear.

I suggested he rotate his flywheel (he had a mechanic doing the work) which was done and he sent me an e-mail saying it had been successful.

Bill

[koan]

I suggested he rotate his flywheel (he had a mechanic doing the work) which was done and he sent me an e-mail saying it had been successful.

Good to know "offsetting" the ring gear works on an eight, was a bit wary about suggesting it.  It will work on a four as the worn parts are 180 degrees apart but on an eight only 90 apart needing a 45 degree offset.

Just a bit concerned that variables like temperature (friction) and throttle opening when the engine is switched off might affect the stop position enough to negate the 45 offset.

But if it works it works.

koan

[zeppelinboy]

Thanks fro the info. I will give the offsetting a try when I get a couple of spare days. I will be pulling the engine and transmission as a unit as the manual suggests this time though as I am not very fond of what it takes to get the transmission out from underneath the car. I will let you guys know which I prefer afterward.

-Justin

[Big_Richard]

Thanks fro the info. I will give the offsetting a try when I get a couple of spare days. I will be pulling the engine and transmission as a unit as the manual suggests this time though as I am not very fond of what it takes to get the transmission out from underneath the car. I will let you guys know which I prefer afterward.

-Justin

having done it both ways on various cars in the past, i can say without doubt its much easier to take them out as a complete assembly.

assuming you have good quality tools and dont encounter any troublesome fasteners, removal should take all of 2 - 4 hours.