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Garage => Mechanicals => Topic started by: raueda1 on 03 September 2019, 09:53 AM

Title: Criteria for replacing 6.9 gine mounts
Post by: raueda1 on 03 September 2019, 09:53 AM
The mounts look to be in surprisingly good shape - not collapsed, cracked or otherwise distressed.  Rubber is still appropriately pliable, neither hardened nor softened.  I suspect that they were replaced at some point.  Is there a strong argument to replace them beyond the usual "it's easy when engine is out and they're pretty cheap, so why not?"  thanks,
Title: Re: Criteria for replacing 6.9 gine mounts
Post by: Randys01 on 05 September 2019, 03:44 AM
They are absolute dogs to do in situ. I'm not sure if they are "cheap' but even if they are a King's ransom, do it now.
Title: Re: Criteria for replacing 6.9 gine mounts
Post by: UTn_boy on 17 September 2019, 05:49 AM
6.9 motor mount are no longer available, and haven't been in a few years.  Mercedes will not offer 6.9 motor mounts any longer.  Even so, you can use mounts for a 450se/sel.  Motor mounts can be deceiving.  They can look good, but as soon as the engine's weight sits atop they can collapse.  Especially if they're an aftermarket brand.  So, "when in Rome....." comes to mind.  RandyS isn't fibbing about how difficult they are to get to when the engine is installed.  If there is any argument then I imagine it's quite fitting regarding the aforementioned. 
Title: Re: Criteria for replacing 6.9 gine mounts
Post by: Mattr on 17 September 2019, 08:48 AM
As someone who's running around with a broken motor mount on one of his cars, I'd say change it while it's easy.
Title: Re: Criteria for replacing 6.9 gine mounts
Post by: TJ 450 on 29 September 2019, 05:36 AM
It's when they are squashed or separated that they need to be replaced. The compound of the original 6.9 ones is a lot harder than the other versions, so although the 450 ones will work they may not last as long, but there isn't any other option.

Tim
Title: Re: Criteria for replacing 6.9 gine mounts
Post by: raueda1 on 29 September 2019, 08:43 AM
It's when they are squashed or separated that they need to be replaced. The compound of the original 6.9 ones is a lot harder than the other versions, so although the 450 ones will work they may not last as long, but there isn't any other option.

Tim
That's what I figured so that's why I asked.  Mine were NOT squashed or separated.  I got new ones anyway.  I'm going to do the thumb-press-durometer test on the old and the new and see how different they feel.  Guess I'll put the new ones in anyway.   Cheers,