Gears Done... Finally!

[1978steven]

What oil did you use? Should be doing mine next week

I'm running Mobil 1 75 90 front and rear for break in purposes, after 1500-2000 miles I'll switch to maybe Lucas or something. The front called for 80-90 sythetic and the rear called for a 75-90 sythetic. I'm one of those guys who likes to use what GM recommends, but they want 34-35 dollars a quart for the Delco synthetic 75-90 for the rear, and 8 or so bucks for the 80-90 synthetic for the front. I can deal with the front stuff, but seriously 34-35 bucks a quart before taxes! They can keep that stuff, and when it goes on sale I'll pick some up.... So I'll break them in with the 75-90 Mobil 1 and go from there.

what is the rpm at 70 mph? i am having 4.56's put in mine and probably a 37" tire. ill be getting the same diff covers also. i got the tranny pan which holds an extra 4.5 quarts already, they make some really nice covers. i dont know how well they would do being bashed on rocks compared to a steel cover but they are definitely quality.

At 70mph with my 35's and the 4.88's I'm pushing mid 2300 to 2400 rpms. Typically 65 mph is what I cruise on the highway and I do that at about 2100-2200 rpms, but I don't think 70 mph at those rpm's is too bad. She has tons of torque now with this gear set, no downshifting up steep grades, she just pulls right along. I can't wait to she how she does with a trailer behind it. My main reasons going with the 4.88's was lots of guys I talked with that rans 35's and had gears all had 4.56's and wished they went with 4.88's, and I plan on 37's when these tires need replaced.

I lucked out on this diff cover, I ended up finding it for sale on GMfullsize. The guy had it on his rear end for 10K and decided to upgrade to the 14sf, I ended up paying $165 shipped from Cali. I believe it goes for $350 or better at 4 Wheel Parts. I would like to get the tranny pan too, but that will have to wait for more funds. Or this dang money fairy!

What kind of oil/additive is recommended? I like that diff cover, I'm going to have to look into getting one

Are you going to re-use your G80? Maybe Gasguzzler could chime in on this to clairify the info I was given. But, from what I was told the G80 does not require a LSD additive or friction modifier. Neither did the True Trac I'm running, just straight sythetic gear oil.

[cjriojas]

I'm running Mobil 1 75 90 front and rear for break in purposes, after 1500-2000 miles I'll switch to maybe Lucas or something. The front called for 80-90 sythetic and the rear called for a 75-90 sythetic. I'm one of those guys who likes to use what GM recommends, but they want 34-35 dollars a quart for the Delco synthetic 75-90 for the rear, and 8 or so bucks for the 80-90 synthetic for the front. I can deal with the front stuff, but seriously 34-35 bucks a quart before taxes! They can keep that stuff, and when it goes on sale I'll pick some up.... So I'll break them in with the 75-90 Mobil 1 and go from there.

Where are you looking?!?! I can find it for $18. Hell, Royal Purples stuff is 17 and change. If you look well enough you can get it for $11 in some places.

[1978steven]

Where are you looking?!?! I can find it for $18. Hell, Royal Purples stuff is 17 and change. If you look well enough you can get it for $11 in some places.

Yeah, I know you can get it cheaper. I was talking about the Delco Synthetic, the dealer wants $34-$35 a quart plus tax.

[cjriojas]

Yeah, I know you can get it cheaper. I was talking about the Delco Synthetic, the dealer wants $34-$35 a quart plus tax.

i was talking about delco synthetic also. i can get it for $18 and if i look hard enough probably cheaper and its not from the stealership.

[1978steven]

i was talking about delco synthetic also. i can get it for $18 and if i look hard enough probably cheaper and its not from the stealership.

Ok, gotch! Dealership around here are stuck at list price, they won't budge much.