GreaseMonky Posted November 28, 2011 Report Share Posted November 28, 2011 Like the title says I am looking for a rear diff for my 610 race car, I have 3.90 in it now, and I need a lower gear, and I am coming up empty handed at the j/y Link to comment
Skib Posted November 28, 2011 Report Share Posted November 28, 2011 is it an R180? what ratio are you looking to get? Link to comment
GreaseMonky Posted November 28, 2011 Author Report Share Posted November 28, 2011 Im not sure if its a 180 or not, its got slide in axles on the diff side, not sure if that helps, i need to get my rpms up about 1500, or more so i was thinking like 4.37, or maybe even lower, I would like to find a whole complete set up, so i can have different gears for different tracks Link to comment
datzenmike Posted November 28, 2011 Report Share Posted November 28, 2011 Stock they were R-160s with 3.70 for 4 speeds and 3.90 for automatics. All L20B 610s were 3.70. R-180 will fit in the same as putting one in a 510. You can get an R-180 from the front of a 720 in these ratios: R-180 4.11 '83 and up 4X4 R-180 4.375 '80-'82.5 4X4 R-180 4.625 '87-'89 Pathfinder equipped with Z24i motor only. 1,500 RPM increase? In what gear what speed what tire size? For example a 24" tire at 50 MPH 4th gear only goes up just under 500 RPM by changing from a 3.90 to a 4.375 diff ratio. Link to comment
GreaseMonky Posted November 28, 2011 Author Report Share Posted November 28, 2011 Stock they were R-160s with 3.70 for 4 speeds and 3.90 for automatics. All L20B 610s were 3.70. R-180 will fit in the same as putting one in a 510. You can get an R-180 from the front of a 720 in these ratios: R-180 4.11 '83 and up 4X4 R-180 4.375 '80-'82.5 4X4 R-180 4.625 '87-'89 Pathfinder equipped with Z24i motor only. 1,500 RPM increase? In what gear what speed what tire size? For example a 24" tire at 50 MPH 4th gear only goes up just under 500 RPM by changing from a 3.90 to a 4.375 diff ratio. Thanks DatzenMike, I remember you responding to my other post, but I figured since I am stricking out with the wrecking yards I would post here in the wanted section. Well my cowl tag says my car is a 74, but RedBanner says it cant be because of the bumpers, but its a 4 speed with 3.90, atleast thats what the sticker says on the diff, but it has push in axels, and most of the pics I am seeing show a flange with bolts, including the R180'S in the front of the 720 I looked at a 81 720 4x4 today, with a z22, and a 4 speed, and the tag on the fender well said it had 3.80 we run second gear only and and I have a 22.7" tall tire according to a tire conversion site I found Link to comment
datzenmike Posted November 28, 2011 Report Share Posted November 28, 2011 Thanks DatzenMike, I remember you responding to my other post, but I figured since I am stricking out with the wrecking yards I would post here in the wanted section. Well my cowl tag says my car is a 74, but RedBanner says it cant be because of the bumpers, but its a 4 speed with 3.90, atleast thats what the sticker says on the diff, but it has push in axels, and most of the pics I am seeing show a flange with bolts, including the R180'S in the front of the 720 I looked at a 81 720 4x4 today, with a z22, and a 4 speed, and the tag on the fender well said it had 3.80 we run second gear only and and I have a 22.7" tall tire according to a tire conversion site I found There were only two ratios used on all 720 4x4s. L20B and Z22 motors '80-Oct '82 used the 4.375 and all after with the Z24 motor were 4.11. Only the automatic and Cab Chassis option had a differential different from a 3.889 in '81. so perhaps someone swapped the engine tag??? As for your '74, during 38 years perhaps the diff blew and an automatic one was mistakenly swapped it. Not at all impossible. BTW I said all L20Bs were 3.7... I meant all 610s after Sept '74 were 3.70. 2nd gear at 4,000 RPMs is 34.42 MPH with a 3.90 ratio rear end. Switching to a 4.375 ratio would drop the speed to 30.68 MPH OR... To keep the same speed of 34.42 the RPMs would go up to 4,486. Switching to a 4.625 ratio rear end and keeping the same top speed of 34.42 MPH would increase the RPMs to 4,743. Link to comment
GreaseMonky Posted November 28, 2011 Author Report Share Posted November 28, 2011 I am going into the corner at about 5000 in second gear, problem is this cam is really just starting to come on at that rpm, and thats when i need to back off the throttle, i did find a 4.625 from a pathy local that I am going to call on tomorrow I hope the price is right, im just not sure if thats going to be to low Link to comment
datzenmike Posted November 28, 2011 Report Share Posted November 28, 2011 5000 RPMs with the 3.90 becomes 5,928 with the 4.625 swap. What tranny are you using??? the stock 4 seed? Second gear has a 2.013 ratio IF, they are a long tail and about 31.5" long (which I believe they are) then a '79 4 or 5 speed from a 620 will fit without changing the driveshaft and only modding the rear mount. The '79 620 and the 80 720 2wd (only) uses a 2.245 ratio second gear and combined with the 4.625 R-180 diff will give you an increase from 5,000 to 6,615 at the same speed. That better??? Link to comment
GreaseMonky Posted November 28, 2011 Author Report Share Posted November 28, 2011 yes that i think would be near perfect, thank you! how do you figure that out? Link to comment
RedBanner Posted November 28, 2011 Report Share Posted November 28, 2011 yes that i think would be near perfect, thank you! how do you figure that out? theres an awsomeness vortex in canada, at least thats what ive heard. Link to comment
Skib Posted November 28, 2011 Report Share Posted November 28, 2011 yes that i think would be near perfect, thank you! how do you figure that out? he didnt get the title KING RAT for nothin theres an awsomeness vortex in canada, at least thats what ive heard. two words. french. canada. whats your excuse...... Link to comment
datzenmike Posted November 28, 2011 Report Share Posted November 28, 2011 theres an awsomeness vortex in canada, at least thats what ive heard. It's affecting the weather. yes that i think would be near perfect, thank you! how do you figure that out? A magician never reveals his secrets. Link to comment
GreaseMonky Posted November 28, 2011 Author Report Share Posted November 28, 2011 you guys are awesome, whats your opinion banner,since you have seen my car, and it race, you think i should pic that diff up tomorrow and give it a shot before the next race? I am a little concerened tho, because my stub shafts look like they just push onto a splined shaft on the diff side and 4 bolts on teh wheel side, and if I remeber right they bolt on the diff side and slide into a hub on the wheel side on the front ends Link to comment
RedBanner Posted November 28, 2011 Report Share Posted November 28, 2011 you guys are awesome, whats your opinion banner,since you have seen my car, and it race, you think i should pic that diff up tomorrow and give it a shot before the next race? I am a little concerened tho, because my stub shafts look like they just push onto a splined shaft on the diff side and 4 bolts on teh wheel side, and if I remeber right they bolt on the diff side and slide into a hub on the wheel side on the front ends Meh........ I ront row.... Link to comment
RedBanner Posted November 28, 2011 Report Share Posted November 28, 2011 James is at the jy right now and he saud that the oathy diffs have a "extension" on them, he just needs the enternals for a gear swap right? Or is he looking at the wrong diff? Link to comment
datzenmike Posted November 28, 2011 Report Share Posted November 28, 2011 The one side has an extension that unbolts. Can't say with any confidence that that's all you have to do. If the price is right you can always get it just for the gears. I think it will work. Don't forget it's an R-180 and those gears won't fit your R-160.... you would have to get an R-180 diff to swap them into. You want to win you have to take chances. Link to comment
RedBanner Posted November 28, 2011 Report Share Posted November 28, 2011 Can you guys tell if this is a subie diff, I asked for better pics, thell show up this afternoon. Link to comment
GreaseMonky Posted November 28, 2011 Author Report Share Posted November 28, 2011 Thanks for posting that banner! I will try and get better pics later. i am wondering if I can put a subaru r160 in? or if thats what i already have? Later subaru impreza have a r160, and you can get them with 4.44 gears Link to comment
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