INFINITY

i am wanting to regear my 80 (32" tires with stock R&P gears front and back, it has the side loader 4speed tranny).
i am also wanting to put in a 5 speed tranny.
so my question is what kind of a difference should i get if i regeared to 4.88s and go with the 5 speed?
according to pirate4x4
L43 4 speed 79 - 80 3.67
L45 4 speed 81 - 82 3.93
L50 5 speed 81 - 82 3.93
L52 5 speed 83 3.93
G52 & G54 5 speed 84 - 88 (Carb) 3.93
W56 5 speed 85 - 95 (EFI) 3.95 Manual Hub Equipped Vehicles 89 and up Have W56, 89 and up ADD vehicles have G58.
so would this give me a lower geared set in the tranny (kind of like having a granny gear)? or how would this end up.

also does anyone know how the bellhousings would line up? did they keep the same bolt pattern from the 20r to the 22re?? i know they are a bit longer but other than that?

camo31_10.50

if you were to swap in a 5spd...i dont think you would see that big of a difference gear wise..unless this is your DD...if so then i would go with a later model tranny and make it fit...but if i do a 5spd swap...im gonna go with a L52 or a G52..i put the L52 in there because i KNOW it will bolt up to my 20R...im not to sure of the G52...so for ease of installation...find a nice barely used or rebuilt L52

coryc85

Infinity, I have a little bit of comparison info for you from a spreadsheet I made to calculate crawl speed, etc

The first comparison is how fast will the truck crawl in LO at idle (assuming about 1k idle speed)
4sp with 4.10s and 32" tires @1000 rpm in 1st gear = 2.77mph
5sp with 4.10s and 32" tires @1000 rpm in 1st gear = 2.59mph

If you switch to 4.88s:
4sp with 4.10s and 32" tires @1000 rpm in 1st gear = 2.33mph
5sp with 4.10s and 32" tires @1000 rpm in 1st gear = 2.18mph

As for Hwy use:
4sp with 4.10s and 32" tires @70mph in 4th gear = 3015 rpm
5sp with 4.10s and 32" tires @70mph in 5th gear = 2563 rpm

4sp with 4.88s and 32" tires @70mph in 4th gear = 3588 rpm
5sp with 4.88s and 32" tires @70mph in 5th gear = 3050 rpm

So essentially you've got 500rpms of difference between the 4.88 and 4.10, once you to to 4.88s it sure would be nice to have the extra gear to drop your Hwy rpms and you get the lower 1st gear for takeoffs. I assume that the bell housings will line up, but honestly I can't say 100% for sure.

brooklee1000

I disagree with coryc85. What you gain on the highway with 4.88's (16%) you would lose with the OD(15%). I have an '82 carbed with 33's, 4.88's, and a 4spd tranny. highway rpm went from 2700 with factory 4.10's to 3200rpm with 4.88's at 65mph. Now, I get 7mpg better than with the 4.10's, and she doesn't bog like hell on the hills(overheated twice). If you put a 5spd, then- if you are re-gearing the diff anyway- I would make that ratio whatever it needed to be to get that "sweet spot" rpm these 20r/22r motors love. My ideal setup would be 5.71 diff ratio with 5spd tranny (%85 overdrive) that would put me overall at 3200 rpm again, with a final crawl ratio of 42:1 in first gear. Or stick with the 4spd and 4.88's. Same final rpm. Let 'er rev! Your 20r will thank you for the higher rpm.

MSR

we put w56's behind 20r's all the time they bolt right up but are longer and larger around than a l43 so drop cross member half an inch and move back about 2 and cut the floorboard and away you go. The 56 is a better trans then either the g52/54 or L52. Use a forward shift w and tcase to reduce cutting floor.

coryc85

Brooklee, were you taking into account the fact that your odometer was off with 33" tires and 4.10 gears when you calculated the 7mpg, meaning that you were actually traveling MORE miles than the odo read because of the larger tires? I have heard some people say that this 22r likes to be revved, I was just surprised to hear a 7mpg difference. Even so, I would still like to have the 5sp with 4.88s if it were me. It is a lower first gear and if you want more revs on the hwy then just leave it in 4th. Its just nice to have that extra gear for me.

brooklee1000

coryc85--I understand your want for the 5spd. The newer ones are stronger. There is a calculation for figuring highway rpm vs tire and gear ratio. Tranny top gear of 4spd(1) x diff ratio (4,1)x mph (65)x constant of 336 divide all by tire size in inches(33) works out to (1x4.1x65x336/33)=2713 rpm at 65 mph. Since my speedo was off, I drove according to the tach speed, and when figuring mileage, i took all this into account backtracking from the odometer reading. I keep very close track of my economy in order to see any affects due to power train changes. I originally had factory 4.10's(17mpg), got some factory 4.38's, and mileage went up 3mpg. It was still underpowered, only a 6% gear change, but the power difference was night and day! Then did the 4.88 install. I recommend it to everybody. More power and better fuel economy. Think about it. From 4.10's to 4.88's, an increase of 16% in gearing, and I went from 17mpg to 24mpg highway(Canadian gallon of 4.54litres/gal---U.S. gallons have 3.78L, so my mileage in U.S. gallons is now around 21-22) A 40% increase!!!! Who wouldn't wanna regear? I am totally convinced that higher rpm is the way to go with these motors.

INFINITY

so if i tried to find a L52 that would bolt right up to my 20r and stock transfer case?
so 1 more ?:
1. all of the 22r/re trannys will bolt up to the 20r bellhousing (except the 81 which has the bell housing/tranny case as one unit)? yes or no.

i have the 4.38 stock gears. i am wanting the 5th gear for a overdrive for cruising on flat hwys.

brooklee1000

The L52 is an L45 with the 5th gear added onto the back of it. Yes, it will bolt up. You can even put the added gearing onto your existing L45(so I've been told) but its the same length, and should be a bolt in replacement. BUT... they have a reputation for input bearing failure. Check it before buying, or installing. Marlin crawler has a replacement kit that uses a larger bearing (requires machining) that will make it bullet proof. I personally have no experience with newer trannies. I believe they will all bolt on to the 20R because it has the same bolt pattern as the 22R (done that myself with an '85). Many of them are different lengths and will affect driveline length, so check with a measuring tape for length before purchase(in case they tell you its an L52, but its not--BUYER BEWARE). Costs go way up when lengthening or shortening d-shafts.

INFINITY

so i picked up a L52 tranny w/ t-case for $100 and the gears look great.
also the flywheel/clutch/t-bearing are all the same for the L43 and the L52.
i will post up once i scrounge up some $ for a new clutch. also the imput shaft bearing on the L52 seems to be in good shape and i hope it stays together.

INFINITY

the tranny /new clutch/ 80 t-case went in fine.
note to anyone else doing this. the lower 2 main mounting bolts from the bellhousing to the block on the L52 need to be about 1/2 inches longer. also the factory tranny hole in the cab floorboard needs to be cut for the new shifter location.
irritated about the tcase now. i am starting another thread about this. when i shift from 2 high to 4high it GRINDS BADLY, wont let me shift unless it is like 5mph or lower. BEFORE THE TRANNY SWAP I COULD GO INTO 4 HIGH GOING LIKE 50MPH so i dont know wtf???

INFINITY

oh yea it is more quicker in 1,2,3 due to the gear increase.

INFINITY

yea so turns out the hubs need to be locked to shift into 4x while in motion (rear shaft turning, front not turning = grinding) man i feel stupid

INFINITY

also for this swap you need 2 tranny to engine bolts that are about 1" longer than what came with the 80 motor/tranny. there is a little bit more "meat" on 2 of the holes on the 5speed housing so the bolts need to be longer to be able to reach the motor.