Ok, I'm looking at trading my C320 for a 04' G35. The guys states in the ad that he replaced the clutch 7 months ago but he thinks the Syncros are going bad because it grinds every now and then.

I have read that there are some common tranny problems with these. What are your experiences with grinding and what have you done to correct it?

I know I used to have a grinding issue with my Jeep Wrangler and put some Redline fluid in it and never had another problem again.

Does anyone run certain fluids to help prevent grinding or other issues?

Your help is MUCh appreciated.
I am trying to get into a G but don't wanna trade my perfectly well maintained Mercedes for a POS just so I can say I own a G.

 

I had some grinding and replaced it with some amsoil. At first it was still grinding after the fluid change, but then it gradually dissappeared . I haven't grind for a couple years now.
Back when it did grind, it would only grind when I shifted at very low RPMs from 1st to 2nd.

Regardless, I'd still be skeptical in purchasing that G if it grinds every single time.

 

Not sure if it grinds every time. Haven't drove it yet... But I will definately see how bad it is before I consider it... I know Redline fluids are up there with Amsoil. Both are rememdies for some small issues.

What type of tranny oil goes in these?

 

The trans on these cars are quite sensitive IMO, some people say OEM, some say Amsoil or Redline.

I think I've seen some people complain about Redline in areas where it gets cold winters. Amsoil or OEM for areas with all 4 weather seasons.

 

It's funny you mention cold weather and Redline cause in the Jeep AX15, it was known for not going into 1st and sometimes 2nd when it was cold and once the Redline was in it, it shifted perfectly in all temps.
My AX15 had over 215k on it when I installed it and after the Redline it shifted perfectly for another 49k until I sold it... Good Stuff.

But I know Amsoil is awesome too!

 

When I bought mine it was grinding mostly 5th gear.
Switched fluids right away to Royal Purple and no more grinding. Smooth shifting ever since.

 

That's what I wanted to hear. Testimonials

 

I never trust used car owners to put in decent products and never know how long they are in there.
It's normally one of the first things I do in any case for peace of mind.

Either way if you want that car, get the owner to change the tranny fluid to your choice. It's not very expensive, but can give you peace of mind before purchase.