T-18 as everyday?

T-18 as everyday?
sponge

sponge

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Libertyville IL
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86 CJ7, a minivan, and an Infiniti G37x
I have a T-18 out of an 82 F250 With the granny gear that I bought to put in when my Jeep was exclusive for trail use.

Well my direction has changed, I want to enjoy my Jeep with my family and street usability is more important.

I haven't put the T-18 in yet, my CJ still has the OEM T-5

The T-5 has served very well as a everyday tranny when below 33" tires, and will again with a regear of the diffs.

My question for you all is will the T-18 serve well as a everyday tranny with highway usage with the right gears or should I stick with my T-5 ?

Keep the sell me the T-18 to yourself for right now...;)
 
I think that if you look at the ratios you will find that the T-18 is like a T-150 3 speed with a granny low. final drive is 1 to 1. your T-5 is .8 to 1 in 5th.

If I thought that good mileage was going to occur I would keep the T-5 for the Overdrive but I don't see that happening. I would not be letting the T-18 get away just yet I think you should get things running and then give this serious thought.:cool:
 
:agree:

And you can sell me... just kidding :D

Like IO said, the Overdrive gear in your current tranny makes a difference on long freeway trips... but a T-18 is a great option if you ever do want to crawl off road with it as well...
 
JR74CJ5 said:
:agree:

And you can sell me... just kidding :D

Like IO said, the Overdrive gear in your current tranny makes a difference on long freeway trips... but a T-18 is a great option if you ever do want to crawl off road with it as well...
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:)I agree with all of the above.............its just an overgrown 3 speed with a narly tree climbing low gear, you or your Jeep will not know the difference in First,second or third.
:D:D:D:D
 
I hear this alot. My '78 CJ5 had the T-150 in it and I could run the highway all day long at 70 + with 4.10s 33s and a 360. I dont see anything that would make the T-18 a problem for you. And while you may have had good "luck" with the T-5 I believe its only a matter of time. Then you'll really regret dumping the T-18 . These are just my opinions though. :)

IOPort51 said:
I think that if you look at the ratios you will find that the T-18 is like a T-150 3 speed with a granny low. final drive is 1 to 1. your T-5 is .8 to 1 in 5th.
Click to expand...
 
I wouldn’t put money into a T-5 but that’s me. There is a thread on this issues from the other day http://www.jeep-cj.com/forums/f2/gearing-change-automatic-trans-14544/ but relates to gearing in the pumpkins as opposed to the Transmission ; the net result on the road or trail is the same with both posts. I have a T-18 wide ratio, 4.56 gears in the diffs, with 33” tires and as I state in the other post I am not happy with the highway performance as the AMC V8 turns at over 3K at 65 mph.

To offset this issue I want to put a TeraLo kit in the Transfer Case and change out the pumpkins to something taller (numerically lower) so that when in low gear in both the Transmission & Transfer Case the crawl ratio will be the same or better than it is but also lower the highway rpm. Not sure what those numbers are yet but will be working on it.

So if it was my call in your case, the T-18 would get the nod and just drive it like a 3 speed starting in 2nd unless wheeling. Here are a couple of sites that may help you out with the swap.

http://www.jeeptech.com/convtrans/ford/fordt18id.html

http://www.jeeptech.com/convtrans/cjt18/
 
Thanks guys for the feedback, I will hang onto it until the T-5 dies.

I plan to regear the diffs to 4.10 this summer with hopes it will get the jeep back to more street drivable...right now the lockers are awful on the street and 5th gear is pointless
 
I think that is a good choice. The T-5 shifts very well for street duty and it is a smooth tranny. The T-18 although very strong is old and mine at least is very sloppy. I do not like the gearing around town and compared to my old T-176 I would prefer it over the T-18 for street duty as well. I keep the T-18 mainly because it is backing a powerful V8 and is needed for the application. My Scrambler will be using the stock T-5 with the AMC 258 i6 / 4.2l for street only duty.
 
Kane said:
I think that is a good choice. The T-5 shifts very well for street duty and it is a smooth tranny. The T-18 although very strong is old and mine at least is very sloppy. I do not like the gearing around town and compared to my old T-176 I would prefer it over the T-18 for street duty as well. I keep the T-18 mainly because it is backing a powerful V8 and is needed for the application. My Scrambler will be using the stock T-5 with the AMC 258 i6 / 4.2l for street only duty.
Click to expand...

This was my thought, thanks for the feed back it I'd really helpful to hear from some one who has used and drives both.

I may hang onto it for a bit...but the cash from selling it would be nice:rolleyes:

Hopefully th T-5 holds up for a while...
 
I have been daily driving my dads 83 CJ5 lately. It's has a AMC 258 i6 / 4.2l with Mopar fuel injection and a T-18 . Behind that there is a Dana 300 and 4:10 axle gears. I try to avoid the freeway as much as possible when driving it. It can do 65 but the rpms are up there... Enough that I only take it up to 55-60 unless I really need to go faster. As far as shifting... You start in 2nd gear unless your in really slow traffic or something. The tranny felt really loose when I first started driving it but you get used to it. It actually speed shifts pretty nicely as well. I only use the clutch when stopping or if I need to down shift very quickly.

I don't think you mentioned what model cj this is for, but in my dads CJ5 the drive line ended up being very short.

I hope this helps...
 
This is my experience, my CJ5 had 3.73 gears running a t-18a with 33's it would run 75 mph, fuel milage wasn't the best but it would do it. Mind you I was running a ford 302 in that jeep. I use to drive it 70 miles round trip.
I'm in the same boat as you are with my CJ7 . I've been crunching the numbers with the T-18 running 33's, 4.10 gears At 75mph you will be running 3131 rpms Not an ideal rpm for highway
 
sponge said:
This was my thought, thanks for the feed back it I'd really helpful to hear from some one who has used and drives both.

I may hang onto it for a bit...but the cash from selling it would be nice:rolleyes:

Hopefully th T-5 holds up for a while...
Click to expand...


My 84 CJ7 had 31 inch tires with a Limited slip in the back. I ran this at moab a few times on trails like gold bar rim and poison spider mesa. I never worried about it blowing up and back in 1994 no one really talked about these as being terrible. I really liked it actually.
 
^You had a T-5 ?

I have actually been pretty happy with mine, until I put 33's on...may be cheaper to go back to 32's vs. re-gearing the both diffs.
 
If you want something that has a low crawl gear and yet gets good freeway mileage that may be next to impossible............The Transfer Case is the only place where you can make that difference up short of a 5 speed or an Overdrive like a Warn in a D-18/20.
Re-gear your Transfer Case and leave your 3.73 gears in the back.
 
tarry99 said:
If you want something that has a low crawl gear and yet gets good freeway mileage that may be next to impossible............The Transfer Case is the only place where you can make that difference up short of a 5 speed or an Overdrive like a Warn in a D-18/20.
Re-gear your Transfer Case and leave your 3.73 gears in the back.
Click to expand...

This is the same idea I have been working contemplating, lowering the Transfer Case gearing and raising the differential gears. Let’s look at crawl ratios first. In my case with a wide ratio T-18 , stock Dana 300 , and 4.56 gears in the diffs the ratio works out as follows: 6.32 x 2.62 x 4.56 = 75.51. Around an 80 crawl ratio is good by most standards for the average wheeler, 100 is pretty good, and anything more is just wow for the average wheeler. This setup however with 33” tires turns just over 3K at 65 mph; more than I would like.

However change the Transfer Case to 4.0 with a TeraLow kit and you get: 6.32 x 4.0 x 4.56 = 115.28 but the highway stays the same. Bump up the differentials to 3.73 as an example and you get: 6.32 x 4.0 x 3.73 = 94.29 with a highway rpm of just under 2.5K at 65 mph. The only drawback I see is that depending upon what type of wheeling you do a real low crawl ratio may not always be a good thing; mud and sand for example where more tire spin is needed to push the jeep along. I live in the Pacific Nortwest where mud & sand dunes are common place without a lick of slick rock in site. I guess a little more noodling is needed on this one…..
 
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Keep in mind that most all CJ trannies had a 1:1 top gear (only the last few years were available with an Overdrive and most of those trannies were not very good) so for on-road it doesn't matter if it is a 176, AMC 150 , 90, or 18a. It would seem that a swap to something like an NV4500 would offer the compromise needed, as well. My KJ with the NSG370 6 spd and 241 transfer with 3.55 gears and 31" tires has a 48.20:1 crawl ratio yet only turns 2076 at 65.

People love really high crawl-ratios but unless all you do is crawl or you have a very weak motor those triple digit numbers are not needed and hurt you in other situations as mentioned. Stock crawl ratios are 20-25:1 for the majority of our CJ's so winding up around a 50:1 crawl ratio is a major improvement and a number that works well in different terrains. The great thing about a manual Transmission is that you don't have to start out in first in low range. Need more wheel speed? How about 3rd gear or even 4th gear in low? Use the Transfer Case like a splitter in a big rig and you now have 8 forward gears..don't be afraid to use them.

My CJ (T18a/Dana 20 /4.56/38's):

Tcase...High...........................Low
1st......28.82.........................58.50
2nd.....14.09..........................28.60
3rd......7.71...........................15.64
4th......4.56...........................9.26

You can see that starting in Low/2nd = Hi/1st. Low/3rd = Hi/2nd. Put it in low range and drive around in 2nd or 3rd until you need the lower range.
 
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