New Tranny or new Gears

[J10nLa]

i have a 1983 J10 with a 258,T176,and anp 208 x case.my problem is no power when towing and overall tranny strength.i had the transmission rebuilt about 8 months ago and at the time the mechanic told me that the T176 was a weak transmision and i shouldnt tow with it.i know that part of my problem is poor gearing (2.72).
my questions are as follows:
is this transmission weak ?
should i opt for a new transmision ,such as a T 18 , or should i just change the gearing .
any help or comments will be appreciated.

[reddog]

I am not familar with the t176 but 2.72 gears are too high for much towing - especially with the 258. IMHO the gears should be changed if your going tow much weight at all, no matter what trans you have.

[Coley]

J10nLa,
What part of LA are you in?

[scotty]

the t176 is a medium duty trans.its far better than the t4,and some of the other aluminum cased ones,but definately nowhere near the strength of a t18. it depends on what you tow and how often. one thing to consider is that you have a half ton truck with a front 44 and an amc 20,yes? the pinion is quite a bit bigger on the amc 20-1.62 in vs the 1.37 on the 44. the lower the gears the smaller the pinion,and the 44 isnt real big to start. the pinion is the same size as the pinion on a dana 60,and id say you could go lower on the gears without worrying too uch about breaking pinions with the 20,like you would if you had a rear dana 44. the front prolly isnt as much of a concern,since you dont usually tow in 4wd,right?

assuming the t176 has a first gear of about 3 to 1(it may not be that low) in high range,final drive in first is only 8.16 to 1. swap in a t18 with a its 6.39 granny,and your first final drive jumps up to 17.3-which is alittle more than twice!in order to get that with a t176,youll need somewhere around a 5.90 axle gear,which will definately kill any hopes you had of a resonable top speed and some fuel economy.

how much power do you have while in 4th gear? is it sluggish? you may need slightly lower axle gears to get the rpms up to a more useable range with a heavy load. wether you lower the axle gears slightly or not,i defiantely think your best bet for towing with the tough little 258 is a t18 swap.

a couple of words on that: the only truck a t18a was used with a driver side NP case is the 80 and up j20,which are not real common,and only avaialbe engine in a j20(to my knowledge) is the 360,at least in the 80 and up animals. this means that when you locate your t18a and 208,they will have the spacer between the belhousing and tranny to accomodate for the further forward plcement of the 360 in the engine compt. put this version in your truck and the shifter is gonna be further back than it should be.the 208 will need a longer rod to reach the stock shifter.and of course new driveshafts. you can a) swap input shafts and remove the spacer,creatig a 6 cyl t18,or b) not worry too much about it. this is what im gonna do. as far as i can tell the v8 t18 in my GW will need a custom crossmember,and hopefully the stock 77 shifter will not cause too much seat interferance. i prolly will have to give up my console for the spicer 18 shift levers,and the levers for the PTO and drum E brake.

last and not least, your clutch linkage will be slightly different,and the t18a 208 uses a unique 31 spline output,so make sure you get the matching xfer case,your t176 208 has 23 splines and wont bolt up. we re in the process of putting a ford 205 onto my frineds 82 t18a,so if a heavy duty,gear driven,iron cased xfer case interests you,stay tuned.

the cheapest way to get the t18 and better gears might be consider getting a 79 or older parts truck with lower gears.swap the whole axle assemblies to get the lower gears and passenger side diff,and now you can use the matching dana 20 xfer.the older t18/dana 20 is alot more common than the 80 and up t18/208,and better suited to towing,IMO.tho this route may be more physical labor,at least you wont have to buy and pay someone to set up the gears,and hopefully will be easier to find and cheaper to obtain than the newer t18.

whew! that was alot of typing,just my $.02,hope it helps you out some...


------------------
scott
85 grand wagoneer
258 with motorcraft 2bbl/904/twin stick dana 300/dana 44/welded amc 20
38x15.5 gumbo mudders
snorkel/dual batteries/onboard air/"custom" convertable
3 inch body lift/mostly stock suspension/"modified" fender openings
custom front/rear bumpers and brushgaurd

T18/dana-spicer 18 with drum E brake and PTO swap very soon
searching for offset QT rear and PTO winch


[This message has been edited by scotty (edited November 22, 2000).]

[J10nLa]

thanks to all for comments .i think i may have come up with a solution . the early broncos had a dana20 with a drivers drop .now i need to check on the tranny combos . i think i may be looking at a T 18 to a dana 20 drivers side drop will try to keep u informed.

[scotty]

definately let me know the results.i was under the inpression that the bronco 20 used a different mounting pattern.

[J10nLa]

the bronco 20 is a different pattern so its back to the drawing board .am also looking into T18 or 19 with advance adapter x case adapter.

[Shane]

J10nLA you will still find that you will want lower axle gear ratios even if you do swap tranys. I know this because my '82 J10 with 258 and 2.73's is barely powerful enough to pull me along on the "flat lands" of Saskatchewan. My T5 trany has overdrive and is not even needed, in 4th gear at 60mph I only rev at about 2050rpm. I think we both need to do some gear changes.

Shane

------------------
1982 J10 Model 25 Pioneer
My Daily driver since 1988
D44,258(.030" over),T5,NP208,AMC20

[joe]

Hi J10nla,
I've sorta been following this thread and the advice you've gotten is correct. I see you also talking Broncos, D20's blah blah...you're missing the point here. All trannies except ones with OD(be even worse for you) and all transfer cases all have a final drive ratio of 1:1 in hi range and/or hi gear. No matter what flavor/brand tranny/x-case you swap to it isn't going to change zip so far as road towing goes, they all still have a 1:1 final ratio same as you have right now. You "really" do need to change out those rediculous 2.73 axle gears if you want to tow. Scotty's et al advice for a T-18A trans swap is great for a strength up grade and even a D20 swap for the same reason they but won't change a thing going down the road towing. Again it's all a 1:1 final ratio regardless of what you've got in front of the axles. The axle ratio is your towing problem.
-joe

[scotty]

by the time that you buy a ford t18 or t19(which has a slightly higher first,i think) and the AA parts needed to mate it to your np 208,you could prolly have bought a 79 or older parts truck.the d20s low range is higher,but IMO its worth swapping axles to have a gear drive xfer for towing. if you really need the lower low range for 'wheelin(or other pulling) you can swap the bronco 20 gears in to get a 2.49 low,or you can spring some $$ for aftermarket 3.15 gears. if youre really crafty you can maybe find an older j20 which will have a rear dana 60(much stronger than amc 20 or dana 44) and will likely have at least 3.73 gears.

no matter how you do it,good luck with your project...



------------------
scott
85 grand wagoneer
258 with motorcraft 2bbl/904/twin stick dana 300/dana 44/welded amc 20
38x15.5 gumbo mudders
snorkel/dual batteries/onboard air/"custom" convertable
3 inch body lift/mostly stock suspension/"modified" fender openings
custom front/rear bumpers and brushgaurd

T18/dana-spicer 18 with drum E brake and PTO swap very soon
searching for offset QT rear and PTO winch

[J10nLa]

when going down the road i dont really have a problem .it is just when i am getting started in first (terminal clutch burning).but i do agree gears are also in order

[joe]

<BLOCKQUOTE>quote:</font><HR>Originally posted by J10nLa:
when going down the road i dont really have a problem .it is just when i am getting started in first (terminal clutch burning).but i do agree gears are also in order<HR></BLOCKQUOTE>

Lower axle gears will make a big diff in off the line starting too even with your stock trans.
Effective gearing is trans gear X tcase gear X axle gear. So no matter what trans you run in hi gear with the tcase in hi your at 1x1x2.73
The T-176 has a 1st gear of 3.82 which isn't terrible so in first you've got 3.82x1x2.73=10.4 which yeah is a b*tch on a clutch because of the axle gears.
With say 3.73 gears in the axles and your stock trans/tcase you've bumped the numbers to 3.82x1x3.73=14.2 which is almost half again improvement over what you have now. If you do serious towing 4.10 gears get you to 3.82x1x4.1=15.7 even better and this is all with your stock trans. Sure the 6.32 low of a T-18A will get you to 17.2 but once you're out of granny gear(within a few feet) you're right back to zip you were with the T-176 because you can't wind granny gear near as long(mph) as 1st in a higher ratio trans. Granny gear isn't much for towing cause you're only in it momentarily just to get a "really heavy" load rolling. Nothing you want to do at every stop sign or in traffic.
For towing the biggest bang for the buck is new axle gears first. If you can upgrade the trans too that's cool but a good T-18A, possible rebuild, possible input shaft, adapters etc can cost as much as swapping the axle gears which you need anyway. A trans swap is a bonus not a neccessity as the axle gears are.
Just my two cents http://www.ifsja.org/ubb/smile.gif
-joe

[scotty]

just wanted to point out that the lower the axle gears,the higher the engine rpm is in the 1 to 1 high gear. you will have more useable power in high gear to a point,but there is a line where fuel economy will suffer,top speed is lower,and engine wear will be alot higher. you dont want it to lug in high gear,but you dont want it screaming at 3500 rpm at 65 mph either. you also need to factor in actual tire size to the final drive to calculate engine rpm at a given speed. there is a formula,but i cant remember it.

is this something youll drive everyday,or a work only towing truck? those factors will have a say as well. if its a daily driver,performance/economy while unloaded should also be considered.if its only used to pull,then youll want to maximize performance for that.if youre happy with 2.73 gears in high gear,while towing,or unloaded,swap the tranny first and see how ya like it. the t18 will definately help you get it rolling without slipping the clutch,and you can run 2nd out to a reasonable speed-2nd in a t18 is 3.09 to 1,as low as the first in alot of other manual trannies. we just swapped an sm 465 into my friends full size GMC and he loves it.when we pulled the j20 parts truck home,he started out in granny at every light,and he loved it-was much better towing with the granny 4 spd that with the previous auto.no biggie to start in granny with a load,just make sure youre at a dead stop,since granny 1st is not synchronised.

im still casting my vote for parts truck.if you buy new gears,and pay someone else to set them up,itwill cost you lots of $$.if you buy a ford tranny and AA parts to mate it to a 208,youll again pay lots of $$. keep your eyeballs peeled for awhile and youre likely to run into a 79 or so j10 with a t18 and 3.55 or lower gears for $500 or less. maybe the frame/body is rusty or broken,maybe the engine is gone,and the interior is shot-but youve got your gears and a tranny. if you buy new R&Ps it will easily cost you way upwards of $500 per axle to buy gears,install kits,and pay someone else to do the labor,unless youve got the neccessary tools to set up an axle youself.plus you can maybe make some back by selling off the glass,doors,seat,and lots of other small items.

maybe my opinion is alittle biased- i love parts trucks.we just bought a 77 j20 that ran for $300.we split the cost up between 3 of us and i ended up with my t18/d20 clutch pedals,etc. for $100. i was very happy. the only problem is that you need somewhere to disassemble said vehicle,which can be a problem. i have seen other guys buy a 3/4 or 1 ton parts truck that runs,swap in their 1/2 ton axles or tranny,engine,whatever, and then resell the truck as a functional,operational vehicle for what they paid for it or more,if you polish it up alittle.

oops-got off the subject,didnt i?you get the point anyway,parts trucks are great.

------------------
scott
85 grand wagoneer
258 with motorcraft 2bbl/904/twin stick dana 300/dana 44/welded amc 20
38x15.5 gumbo mudders
snorkel/dual batteries/onboard air/"custom" convertable
3 inch body lift/mostly stock suspension/"modified" fender openings
custom front/rear bumpers and brushgaurd

T18/dana-spicer 18 with drum E brake and PTO swap very soon
searching for offset QT rear and PTO winch

[This message has been edited by scotty (edited November 24, 2000).]

[Slippery]

<BLOCKQUOTE>quote:</font><HR>Originally posted by scotty:
parts trucks are great.<HR></BLOCKQUOTE>

Try convincing my wife...

[J10nLa]

thanks for all the help.i think i will go for the gears (maybe parts truck axles)first depending on what i can find . but i must say i did get many interesting opinions on this and after i get the change in gears i will let u know how it goes.thanks again to everyone.