I guess what I was asking is what is RP? Redline?

 

I put in Amsoil 75w140 in late fall, my car is in winter storage right now so I haven't driven it too much. I ran Amsoil 75w110 last summer, I want to try the thicker visc this year to see how it compares, I'm going to have the fluid analyzed at the end of summer. I did a used fluid analysis of the 75w110 but it got lost in the mail last year and I couldn't re-sample, aaaaaargh !.

If you go with any fluid make sure it is a real group 4/5 synthetic so you get the cold temp flow properties, it will flow way better than any conventional, semi-synthetic or group 3 synthetic. I like to look at the manufacturer specs to see how it flows at cold temps. I like the Amsoil product line, and it will work well in cold temps. If you go to Amsoil's website you can see all of the cold temp flow specs for all of their gear oil viscosities, it is very helpful. I find the LSD seems to work smoother and more consistently with thicker viscosity fluids. My car came with 75w90, I switched to 75w110 first and now 75w140.

 

RP=Royal Purple

 

I changed my diff fluid a couple of days ago, and I chose Mobil 1 75w-90.

Living in Texas, I won't be needing any cold weather protection for quite a while. I have never beat on my car (ie hard launches etc) so I'm sure this will be ok.

 

yup, it seems to work quite well on our diffs , another good choice.

 

Another satisfied Amsoil customer here. 75w-110 is what I chose after analyzing countless posts from all the great (more experienced)members on this board. I just ordered directly off Amsoil's site, and bought the fluid pump that fits just right on their quart bottle. Made thiings pretty easy but it's still not a fun job.

 

I changed mine yesterday. I got amsoil 75w90 and a 2 way suction pump from autozone. I have to say it was prolly the easiest thing I have done thus far.

 

I live just west of Magnolia (probably about 50 miles north from you). I have a good jack and jack stands with plenty of LE1605, AMSOIL MTF, and LE8130 (10W-30) on hand too. I'll let you set up shop for the day in the garage or driveway to get er done. I have all the tools and some brake fluid too so you can bleed the brakes and clutch. Don't know how? I'll show you.

 

You probably also need to flush the coolant/antifreeze too. You should take it to a shop for that. I don't have anywhere to toss the old coolant.