Pirate 4x4 banner

1 - 20 of 28 Posts

·
Registered
Joined
·
3,131 Posts
Discussion Starter #1
How many of you people still run a jeep D20? I have a 74 cj5 with 258 to T18 to D20 and want lower gears without changing my drivetrain around. What gears sets are out there for the D20 that are reasonably priced? I know tera makes a set but does any one else? How can I get lower crawl ratio?
 

·
Registered
Joined
·
3,939 Posts
Obriens' (sp)
tera
bronco gears.

Those are your options. I run a 20 with 18 gears (same as a bronco 20) with a healthy v8 and they work fine. Get's me 103:1 low range also. Upgraded the rear output though.
 

·
Registered
Joined
·
475 Posts
I've got a tera-lo (3.15:1) dana 20 behind a T18 & 401. I also upgraded w/ the AA output and twin sticks (w/ dana 18 & scout dana 20 parts). It's held up just fine so far, but I've heard of people destroying the tera lo gears. It also makes for a nice short drive train.

In retrospect, I should have gone w/ the ATLAS it wouldn't have been that much more expensive, I'd have a better crawl ratio, and I'd never have to worry about it.

search, this has been discussed before.
 

·
Registered
Joined
·
1,658 Posts
I have been using the 4.86:1 O'brien gears in a bronco 20 for 5 years now. Work awesome.
 

·
Registered
Joined
·
122 Posts
I have run the tera low 3.15 kit since 99 with not probs, a buddy has the same kit and had problems but it was a worn bearing in the output shaft that was the culprit,,,
 

·
Registered
Joined
·
3,749 Posts
Do you have the 4:1 T-18 or the 6:1 T-18? If you only have the 4:1 you might consider regearing that.
 

·
Registered
Joined
·
3,131 Posts
Discussion Starter #8
Grandpa Jeep said:
Do you have the 4:1 T-18 or the 6:1 T-18? If you only have the 4:1 you might consider regearing that.

How do you tell? It's the stock trans that came in the jeep(74 cj5)
 

·
Premium Member
Joined
·
3,919 Posts
I would highly advise against going the tera route. 2 guys in our club ran tera's with v-6's, 33's, powerlok's, and busted 5 sets between them. Search other posts for tera.
 

·
Registered
Joined
·
3,749 Posts
TOY 2 said:



How do you tell? It's the stock trans that came in the jeep(74 cj5)
I believe the stock trans for a 74 CJ is the 4:1 version. With the trans in the vehicle, the easiest way to tell for sure is to pull the top cover and count the teeth on the input gear. A 6:1 tranny will have 17 teeth on this gear, and a 4:1 case will have 22 teeth.
 

·
Premium Member
Joined
·
1,175 Posts
TOY 2 said:

I looked on jess site and couldn't find any 4:1 for a Dana 20?
There is no 4:1
Terra is 3.15:1
O'Brien makes 3.1 and 3.6:1

O'Brien's gears are better quality, but cost twice as much. (916) 773-3278
 

·
Registered
Joined
·
56 Posts
ok sorry to get into this but im confused i might be mistaken but im lost i think im reading that theres a 6:1 ration in the t-case or are u talkin about the t-18a? and then ive never heard of the 4.86 in a t-case either just curious about these facts of if they were just typos.
 

·
Premium Member
Joined
·
1,175 Posts
Last I knew O'Brien did not have a web site.

He makes a 4.1:1 & 4.86:1 for EB D20 whick is completely different from a Jeep D20. They also work in a D18 w/ major case mods.
 

·
Registered
Joined
·
753 Posts
I an rinning a T-18 (6.32:1) and a Dana 20 and a Tera low kit....

No problems with the tera gears themselves....
To fit the gears you have to slightly grind the case to fit the rear output sliding gear

In November I had some "gear-walk" on the rear output sliding gear that busted my t-case housing in two !!!
I'm not sure what caused the gear walk, I believe it was a combination of the shock of breaking a rear driveshaft and "loose" rear output shaft bearings....

The gears held up fine, I just got done putting them into another t-case ... (been running stock d-20 in the meantime)

Heres a pic of the busted case
 
1 - 20 of 28 Posts
Top