My 97 is shifting a little stiff any suggestions on making her a little smoother. No grinding or popping out of gear, just looking for suggestions on fluid change or anything else.

Thanks

Mud

 

I recently changed mine to AMSOIL syncromesh what a difference it made. before I could not downshift and shifting was stiff with the syncromesh oil I can downshift every gear but second.
I have run mobil 1 synthetic atf, mobil 1 synthetic 5w20 motor oil. and now the syncromesh

 

I'm running royal purple and it seems fine. No shifting issues. Almost 30k on it.

 

I always wondered if Syncromesh could be run in these trans. I have gallons of it from my days at the GM garage

 

I have a spare ZF5-47 with a transfer case on it sitting on my shelf, 85,000 miles on it. so i don't mind trying different things.

 

I have a spare couple too, but not worth me risking a $450 rebuild

 

Synchromesh is known for eating syncros of certain material/design. I think it's too aggressive or not slippery enough and they wear out.
If it's shifting hard with synthetic ATF (or whatever oem fluid is) then you have other issues.
I run redline shockproof and synchromesh in my awd import trans and my t5, but failure is caused my my heavy foot and hard shifts, not improper fluid.
I'd research what type of syncros are in the zf, and compare to the gm trans and maybe it's compatible.

 

We always put syncromesh in tremec 3550,tko,3650.. made them like butter.

 

But there again, a different transmission

 

Is there any particular Redline fluid that would be considered "best" for our tcase and tranny's?

 

Redline D4 seems to be the most appropriate as it is synthetic and is said to meet the specs for Dex II, Dex III, Merc, and Merc V applications. The ZF calls for Mercon Synthetic ATF in the manual. I'll be using that or Amsoil Torque-Drive on my next swap any time now. Been running RP Max ATF for almost 40k and can tell it's time for refreshing.

 

I stay away from royal purple products except for short term or racing applications.
Daily drivers and work vehicles I stay away from rp because it oxidizes in a short amount of time. I rebuilt the rear axle of my superduty and pressurewashed and degreased the whole thing to start fresh, all new everything, and put rp in the diff. 10k later did an oil analasys and they said I had to change fluid. I researched and quite a few people (at the time) were having the same issues with diffs, and manual trans. No issues with engine or autos from what I remember though.
I'll stick with Schaeffer or Amsoil. I use Mobil 1 to flush the system for 5k and then switch to the good stuff.
I really like redline products for heavy duty applications. Never got to do OA on it though, so I don't know how it lasts long term.

 

Mobil 1 to flush the system!? you must be rich :-)

I run Mobil 1 ATF in mine all the time.

 

Anyone have an opinion on this? Schaeffer Oil | ALL-Trans Supreme® Transmission Fluid for Dexron III and Mercon fluids

 

Haha. Not rich, just crazy. I use Mobil 1 for it's designed lifespan and then change to my preferred oil. So I swap dino motor oil for Mobil 1, wait 5k and replace it. Trans and transfer case also. Diffs I go 10-15k. Or front diff with hubs locked in, one winter or if in summer take it 100 miles with hubs locked in then change it. It's really to only flush and mix with residual dino oil so it don't contaminate the expensive synthetic oil.

I previously only used Mobil 1 products, I still do, but I really prefer Schaeffer products now. I was an Amsoil dealer, I moved from my big welding fab shop in Maine to just outside philly, and don't have a big business anymore so I got out of selling it.
I use Amsoil in atv stuff, Mobil 1 in daily driver cars and trucks, Schaeffer in my work trucks and hot vehicles, and some equipment. My dump truck and big equipment gets Dino oil, because it's already expensive to replace 20-40quarts using cheap oil.

Anyway
I recommend most all Schaeffer oils, and don't see a problem with Amsoil, or Mobil 1. It's only dependent on your budget.