[Zook2510]

Hi everyone, we've got a 1996 coily sierra which is pretty much stock at the moment. We are running ~29 inch muddies on it and looking to go up to 31s at some stage. Been doing some research into switching the transfer case to get the gearing to where it should be for the bigger tyres but getting confused about it!

Can we swap the 1.3L coily t-case for a 1L case? I've read that you need to modify some other bits as well for it to fit? Or would a leafy 1.3 transfer case be better?

And also what is the difference with a switched and non-switched 1L transfer case? We don't have a 4wd dash light in the first place...not sure if we are meant to or not

Any help would be awesome!

[tanshi]

a switch type 1 litre case should fit, but will need the flanges from a Wide track case put on it to match your flanges.

a non switch typre case is vastly different to a switch type, they are much harder to make work for the application

personally i would be looking at more than a 1 litre case for gearing of 31s

[Gwagensteve]

X2 to that. 1.0 litre gearing is borderline with 31's.

Steve.

[Zook2510]

Ok thanks for the info. Sounds like we might need different gearing altogether...however my understanding is that we can't put new gears into the coily t-case? So to change the gearing we would need a WT or 1L transfer case anyway to begin with?

[Marko_SJ]

Zook2510 wrote:

Ok thanks for the info. Sounds like we might need different gearing altogether...however my understanding is that we can't put new gears into the coily t-case? So to change the gearing we would need a WT or 1L transfer case anyway to begin with?

Yes.

[JrZook]

^^ yup that is correcto. I would be looking at some reduction gears. As Steve said the 1L gears are very borderline especially with anything above 29's. Descent amount of work for minimal gains compared to installing reduction gears.

[Zook2510]

Cheers thanks for the clarification.

Does anyone have any particular reduction gears/ratios/manufacturers that they would recommend? We are using the zook mainly for off-roading, bit of rock crawling etc (so not using it as a DD but still need to get to off road spots on the highway!) and also a few beach trips.

[tanshi]

for 31s i personally like 4.9s from lowrangeoffroad.

others will say the 6.5s are good but i personally find them too low.

[JrZook]

Beach + general wheeling = 4.9's. Even 4:1's would be a huge step up from what you have.

[biff10]

I've got 4.9.1s in my coily with 31s and if you ask me they are perfect for dunes and slow as when you want to crawl, the 3:9 diff in the coily helps to,

Revs at 3800 doing 100 tho

[Zook2510]

Ok thanks for all the advice its definitely cleared things up for us!

[Zook2510]

Actually just have one more question...priced up some reduction gears but a little out of our budget at the minute. Also thought some more about tyres and realised our current muddies are only about 27 inches lol. So prob gonna run 30s and drop a 1L t case in for now.

I just want to check that we need WT flanges to fit it? Plus the leafy jackshaft.

Cheers

[coily96]

If you have trouble finding 1.3 WT flanges you can also use 1.0 NT and 1.3 NT yokes and join them to the coily shafts.

A shorter jackshaft will still be needed with NT yoke

[Zook2510]

Ok thanks. Would a NT jackshaft work (we will have 1L t-case with WT flanges) or does it have to be a WT jackshaft?

[tanshi]

you could redrill the WT flange to fit the NT jack shaft i believe

[Zook2510]

Ta. Should have it sorted now I think lol. We'll see.

[Zook2510]

Help needed please! We have got our 1L transfer case fitted with WT flanges and also a WT jackshaft. Just pulled the original transfer case etc out of the coily and went to put the new one in, but the two mounts (of four bolts each) don't line up!! Were we went to get new mounts as well??

[coily96]

Same mounts, it should go straight in.

[Zook2510]

So the 1L transfer case should bolt straight onto the coily mounts? Have tried and couldn't get it to line up for some reason.Also got some WT mounts hut they don't seem right either. The gear shift lever seems to be stopping us from getting the correct angle.

[JrZook]

Have you tried taking out the gear shift lever and installing that last?

[tanshi]

x2 take the gear stick out.

[Zook2510]

All sorted, thanks everyone, turns out that when the case was rebuilt before we bought it the gearshift was put back in the wrong way! Now to go have some fun