80 4X4 Next mystery 4.88 Rear Diff ????????????
#1
80 4X4 Next mystery 4.88 Rear Diff (SOLVED FOR NOW) THANKS
Now I need a new rear diff and I would like to get a complete 3rd member.
1 Mystery ONE.. I counted my drive line and came up with 4.8 revolutions.. I do not see a 4.88 ever being used in 79-83. Am I to assume some one stuck in a 4.88??? I am turning 3500 rpm at 60 with 30 inch tires. Sound right????
2 Mystery TWO .. Does anyone know of anyone who sells toyota 3rd members with 4.88's ???
3 Mystery THREE Is it possible to get a clutch type posi traction for this rig??
thanks
mark
1 Mystery ONE.. I counted my drive line and came up with 4.8 revolutions.. I do not see a 4.88 ever being used in 79-83. Am I to assume some one stuck in a 4.88??? I am turning 3500 rpm at 60 with 30 inch tires. Sound right????
2 Mystery TWO .. Does anyone know of anyone who sells toyota 3rd members with 4.88's ???
3 Mystery THREE Is it possible to get a clutch type posi traction for this rig??
thanks
mark
Last edited by 69800; Nov 26, 2009 at 04:46 PM. Reason: new status
#2
#5
so did you count the front Diff spin too? remember 4x4 implies matching numbers front & rear are needed. The count the rotations method is very subjective
do some math with this gear calculator:
http://www.csgnetwork.com/gearratcalc.html
using your numbers and that link shows that you have 5.208333333333333 which is more than likely 5.29's --lucky dog you-- you are golden for a set of 35's
edit: with 30" tires, @ 60 mph if you had 4.88's you would be turning about 3250rpm's
Mystery #2 solved: just about every gear house sells 4.88s for a 8" 4 cyl toy diff.
my googling crystal ball was cracked so I used my memory:
trail-gear, randy's ring & pinion, marlin crawler, All-pro, Yukon gear, Motive gear
but you seem to need 5.29's
do some math with this gear calculator:
http://www.csgnetwork.com/gearratcalc.html
using your numbers and that link shows that you have 5.208333333333333 which is more than likely 5.29's --lucky dog you-- you are golden for a set of 35's
edit: with 30" tires, @ 60 mph if you had 4.88's you would be turning about 3250rpm's
Mystery #2 solved: just about every gear house sells 4.88s for a 8" 4 cyl toy diff.
my googling crystal ball was cracked so I used my memory:
trail-gear, randy's ring & pinion, marlin crawler, All-pro, Yukon gear, Motive gear
but you seem to need 5.29's
Last edited by dropzone; Nov 20, 2009 at 05:11 AM.
#6
BUT, if you're keeping 30x9.50's on there, man, you really don't want 5.29's. Sell em and buy yourself either some stock gears, or maybe 4.56's. 30x9.50's are darn close to stock, so you don't even need to anything over 4.10's with them, although a slightly lower gear ratio would help with power a bit.
If, as I'm assuming, you're going for a stock-ish truck, 5.29's are just crazy. 5th gear, 3500 at 60 is not ideal...not if you ever plan on driving 70..
If, as I'm assuming, you're going for a stock-ish truck, 5.29's are just crazy. 5th gear, 3500 at 60 is not ideal...not if you ever plan on driving 70..
Trending Topics
#11
Remember I still have the 4 speed in here so every thing is base on 4th gear. The tires are 30x9.5x15s, I do not really want the truck any taller than it already is. I never go much faster than 55 as we have no freeways around here. I figure once I get the 5 speed installed that will drop my RPMs down to 3000 at 55 in 5th gear..The speed calculator does not say if its set up for forth or fifth gear so i doubt its accuracy. What if I spin my wheel 20 time and count the drive line turns..Would that not be pretty accurate??
Also the only limited slip unit I can find Is a Detroit but they want 400 buck for it above and beyond the third member I still need. Are there any factory toyota diffs from newer trucks that might work in the 80?
DaveZ said he would ship me a rebuilt 4.88 third member for $349 exchange which I thought was really fair. But I still want a limited slip for snow
mark
Also the only limited slip unit I can find Is a Detroit but they want 400 buck for it above and beyond the third member I still need. Are there any factory toyota diffs from newer trucks that might work in the 80?
DaveZ said he would ship me a rebuilt 4.88 third member for $349 exchange which I thought was really fair. But I still want a limited slip for snow
mark
#12
Davez' price is good and after dealing with him on some orders I feel you will get great service.
http://www.grimmjeeper.com/gears.html
and if these don't work for you google gear calculator
and yep I have the gear ratios for both

spinning a driveshaft is very inaccurate to determine gear ratios...it only takes 30-45 minutes to pull a third...pull yours count the ring gear teeth and divide by the pinion teeth to get a real count
Last edited by dropzone; Nov 20, 2009 at 08:36 PM.
#13
I meaured the tires .....29 inches tall...
I counted the driveline with 20 tire rotation 48 and 1/2 revolutions = 4.88 gears in the diff.
speed test coming after breakfast
I have to find my l-43 gear ratios.. I saw them somewhere
I counted the driveline with 20 tire rotation 48 and 1/2 revolutions = 4.88 gears in the diff.
speed test coming after breakfast
I have to find my l-43 gear ratios.. I saw them somewhere
#14
Spin your tire two times, twenty times wow that is a lot of counting. Make sure you mark your tire and your driveshaft. If your driveshaft rotates almost five turns then you most likely have 4.88's.
edit: Better yet just do what ocdropzone said and remove your rear differential and count and divide and there won't be any more guessing.
edit: Better yet just do what ocdropzone said and remove your rear differential and count and divide and there won't be any more guessing.
Last edited by LiquidSky; Nov 21, 2009 at 03:51 PM.
#16
Oh...just wait! I agree with trying not to do things twice but...with a truck this old, believe me, you'll be tearing multiple things down multiple times! Just wait! The fun is only beginning.
My L52, with 30x9.50's, I'm at about 3000 rpms in 5th gear at somewhere between 65-70mph, I think.
My L52, with 30x9.50's, I'm at about 3000 rpms in 5th gear at somewhere between 65-70mph, I think.
#17
Trans gear ratios here:
http://www.marlincrawler.com/tech/tr...ar-ratio-chart
http://www.marlincrawler.com/tech/tr...ar-ratio-chart
#18
idk if this helps but i can cruise at about 65/70 mph at im at like 2800 - 3100 in my lil toyota??? idk if that helps but thats how that is but im lifting mine and putting bigger tires so it will change.
#19
I plugged every thing into the grimmjeeper.com calculator and it says I have 5.29 rear diff gears. Where you imput the transfer case ratio I tried 2.28 but the numbers were way off, so I used defaut toyota selection at the bottom of the list and it came up with 5.29s. I do not know what they are using for default toyota transfer case ratio however???
#20
I BELLIIEEVVVEEE you should go ahead and buy a 5.29 gear set for the rear....
then take your rear third..and your front third...ship them to my address and i'll ship you my stock 4.10's in my '80 toyota
totally kidding...you'd have to be a dang fool to do a trade like that
just get ya some 33's man..like a set of 33.10.50's!..the height wont be much different..and you'll be close to 3000rpms on the highway
then take your rear third..and your front third...ship them to my address and i'll ship you my stock 4.10's in my '80 toyota
totally kidding...you'd have to be a dang fool to do a trade like that
just get ya some 33's man..like a set of 33.10.50's!..the height wont be much different..and you'll be close to 3000rpms on the highway



