Trail Tough Undertaker

Anything related to 4WDs and 4WDing

Moderator: Committee

Post Reply
User avatar
cj!
Posts: 841
Joined: Thu 09 Aug, 2007 3:54 pm
Location: In a shed building my junk

Trail Tough Undertaker

Post by cj! »

As christover has raised an interest in the Undertaker from Trail Tough I thought that I would start a new thread about it. Some of what I written below was what I wrote in an old thread on auszookers.

Installation instructions

You need to separate the t-case from the trans and the Undertaker gets bolted in between. This shfits your t-case lever further back in the car. As you are still using your t-case the slip yokes still work.

Although the Undertaker is a nice piece of gear and has its place it is not a cheap solution or even ideal for those running small tyres like 31's.

If you look at the gearing change, a 1.5 reduction with no other changes to diff ratios will allow you to run 40" tyres at the same rpm as if you were running the stock 27" tyres.

Now you can always do an R&P swap to help this out. Lets say you want to run 31's so if you initially had 5.125's and could get some 4.3's from a GV you would only be running at around 300rpm more at 110kmh, 4.625's would add 600rpm and 4.875's would add 800rpm and staying with the 5.125's would add 1000rpm. These are approximate figures to give an indication.

So what are you looking at? USD$1295 plus shipping and possibly 5% duty (4wd parts) and 10% GST as you over the $1000 threshold although you may not have to pay depending on how Customs feels. You also need to have both front and rear driveshafts modified, one lengthened and one shortened and balanced and possibly find new R&P's for the front and rear diffs and have them installed as well.

It will not be a cheap excercise for 31's to get more on road performance back but if you were to run 33"-35" then it starts to make sense. For 31's I'd just tweak the motor a little, add crawler gears and call it good. You may find that in a manual you will use 5th less or in a a 4spd auto you use the overdrive less but that is not a biggy, think 3 speed auto in the carby Vit with a 1:1 3rd gear which is the same as the 4 speed auto in 3rd gear (If you have a 3 spd auto and swap the R&P's from 4.625 to 5.125 you have corrected it to run 31's with similar to Factory performance). Now if Trail Tough offered a 1.3 reduction that would be great for anybody looking at 30"to 33" in my book as at least you would avoid the expense of changing the R&P's and still have pretty close to standard performance.

The old 5.83 R&P's that Richmond gear designed for Calmini were actually stronger than the Factory 5.38's and 5.62's that we never saw anyway but I think incorrect setup contributed to a number of failures, plenty manage to kill the Factory 5.125's too while others are still happily driving on the 5.83's. Solid pinion spacers and correct installation would help here.

It does help with the crawl ratio and depending upon what diff ratio and trans you run it with you could have a crawl ratio between 30:1 and 51:1 but you will have lost some of that effectiveness due to larger tyres so you may still end up adding t-case gears into the mix.

Another option would be to just swap out the Vitara t-case for a 1.3 Sierra one. Even with stock gearing in the t-case and the diffs the high range would now be better for most commonly used Vit offroad tyre sizes compared to the Undertaker and the low range will also be better although not quite as much as the Undertaker would change it. The Sierra (1.3) runs 1.409 in high and 2.268 in low compared to a Vitara with an Undertaker at 1.5 in high and 2.724 (1.816 x 1.5) in low.

If you used a 1.0 case it would be 1.580 in high and 2.511 in low and if you had grabbed a coily case (which we just threw out I think) you would have 1.320 in high and 2.123 in low. Swapping in some Series 1 crawler gears would give you 1.580 in high and 4.16 or 4.24 in low depending upon whose gears you used.

In a lwb the Vit the offset rear output of the Sierra t-case doesn't seem to have been an issue according to thase that have done it and the same seems to be the case for the swb Vit as well.

Just some food for thought.

Image

Image

Image

Image
User avatar
christover1
Financial Member
Posts: 3045
Joined: Thu 09 Aug, 2007 5:18 pm
Location: Croydon Victoria Australia
Contact:

Re: Trail Tough Undertaker

Post by christover1 »

After some thinkings and ponderings, I have decided against an undertaker.
Take way too long to save for, and I want to enjoy the Vit now, not in 4 years time :)
Probably a more realistic objective is some t-case gears for me.
Especially as I don't intend going any bigger than 31's
The Auto seems to make up for lack of gearing on road.
And with a decent exhaust and headers, it does the hwys ok.
So I really only need to improve gearing off road mainly.

Been thinking the Sierra t-case idea, but I still prefer to fit some gears into vit case..
Main reason being I've never heard of t-case and/or after market gear failures in vits.

So thats the plan, set of 4:24 gears sometime early next year,
and hunt wreckers for a steel front diff for a locker.
ZOOKS RULE DA BUSH
User avatar
cj!
Posts: 841
Joined: Thu 09 Aug, 2007 3:54 pm
Location: In a shed building my junk

Re: Trail Tough Undertaker

Post by cj! »

Personally I do think that is the right choice for your tyre size.
User avatar
christover1
Financial Member
Posts: 3045
Joined: Thu 09 Aug, 2007 5:18 pm
Location: Croydon Victoria Australia
Contact:

Re: Trail Tough Undertaker

Post by christover1 »

cj! wrote:Personally I do think that is the right choice for your tyre size.
You were very right about Sean at Low Range, his delivery fee is vastly cheaper than the others, so far.
Now to chase money, as Rockmonster is on special right now.

http://www.lowrangeoffroad.com/suzuki/s ... train.html
ZOOKS RULE DA BUSH
Post Reply