xt transfer case

More
17 Feb 2017 18:50 #1 by Len208
Len208 created the topic: xt transfer case
Was not aware that the transfer case lever could be pushed too far forward leaving you in front wheel drive only.I was trying to climb a messy slope wondering why I was not making any progress.It was only Min helping to extricate me that saw back wheels not turning.I thought I had done a half shaft,but put into normal drive and drove out.Paul knott suggested that the box is put into low range first and rear drive checked before locking hubs.Live and learn

Please Log in or Create an account to join the conversation.

More
17 Feb 2017 20:08 #2 by DarrenWebster303
DarrenWebster303 replied the topic: xt transfer case
We have all been trapped by such simple things Len. Thanks for sharing. D.

Please Log in or Create an account to join the conversation.

More
17 Feb 2017 21:40 #3 by Tony Lee
Tony Lee replied the topic: xt transfer case
Yes, made a right fool of myself trying to get up little red after being told the oka would idle up it. Actually did pretty well to get within a couple of metres of the top in front wheel drive.
I had been stopping forward movement of the lever once the 4WD light came on, but found if I pushed it all they way forward (an extra 10mm) then I had 4WD.
My continuing concern is that there is no way of knowing the extent of engagement of the gears so all the drive could be taking place on 1mm of gear engagement. How does one check? I guess there are some sort of idents to show the locations but when i had the gear change rod disconnected to fit the turbo, there didn't seem to be anything obvious

Tony

Please Log in or Create an account to join the conversation.

More
17 Feb 2017 22:11 #4 by dandjcr
dandjcr replied the topic: xt transfer case
Thanks Len, I didn't know you could do that with an Oka and it shouldn't be possible, but the internal design of the NP205 does allow for that configuration (hence the twin shift rods/rails).

Check for any play in the gear shaft linkages to avoid similar problems. If it happens regularly, there may also be wear on the indent system on the transfer case shift rods/rails. They are replaceable but you'd probably have to remove the TC to do it.

I have had our transfer case stuck in neutral before due to linkage problems, which is disconcerting, no drive at all.

The front and rear H-N-L drive functions of the NP205 can be separated using " twin stick shifters ", but it's not something designed into the Oka shift system.

David

David and Janet Ribbans - Oka 148
Oka148 profile here.
Visit our technical and travel blogs: here.

Please Log in or Create an account to join the conversation.

More
18 Feb 2017 08:39 - 18 Feb 2017 11:18 #5 by Rick Whitworth
Rick Whitworth replied the topic: xt transfer case
Made this discovery trying to go over deep washaways in the grey slime alongside the Murray when we first got our OKA. The truck just wanted to skate sideways until we noticed the front guards were completely clogged and no mud at all on the back!

Never had problems since applying the rule to always engage low ratio before things get too nasty so you can test it drives before putting the hubs in. ...makes sense because you're nearly always in the cab when you decide you need low ratio anyway.

I have since experimented with the TC in and out of the truck and it is actually quite tricky to deliberately set the position of the selector so that only the front shaft turns. I have spoken to a number of OKA owners who have tried it and from what I can gather its a bit like sheilas, some do it and some don't. On the same note I think that it has something to do with how it is set up rather than how worn it is.

I believe it relates to the indents on the selector rods inside the TC rather than external linkages. When it is not fully engaged you can see that the rear selector rod is still in neutral and the cross link is not square. Odd setup but it works.

I find there is a knack to shifting the NP205. The truck has to be just rolling enough like spinning a crash box, get it right and its smooth as silk, get it wrong and it won't budge. Have to relearn it every time we go off road.
Last Edit: 18 Feb 2017 11:18 by Rick Whitworth.

Please Log in or Create an account to join the conversation.

More
19 Feb 2017 04:56 #6 by dandjcr
dandjcr replied the topic: xt transfer case
This chart may explain the NP205 shift system.

Front wheel drive only should only be possible if the shift rails are modified (as for a twin stick option) or have some wear/maladjustment.

File Attachment:

File Name: ORDNP205TwinStick.pdf
File Size:62 KB

David and Janet Ribbans - Oka 148
Oka148 profile here.
Visit our technical and travel blogs: here.
Attachments:

Please Log in or Create an account to join the conversation.

More
19 Feb 2017 08:05 #7 by Tony Lee
Tony Lee replied the topic: xt transfer case
As usual, theory and practice are rarely the same thing. 123 had supposedly done less than 100k kilometres and was supposedly stock when it first happened to me. I'm pretty sureit had happened at least a couple of times previously, just that I didn't realise why it wasn't living up to its claimed reputation. Hasn't happened since, but since my sledgehammer reshaping of the rods, I guess I should doublecheck operation before I get into an embarrassing situation again

Tony

Please Log in or Create an account to join the conversation.

More
19 Feb 2017 08:47 - 19 Feb 2017 08:48 #8 by Rick Whitworth
Rick Whitworth replied the topic: xt transfer case
Single shift with standard indents allows only the highlighted selections shown below


Split shift PLUS modified indents allows the other selections shown

A number of OKA owners I have spoken to have found they can get the dotted selection (deliberatley or by accident) where the rear selector is still in neutral and the cross link has not moved far enough to be square with the face of the TC. The 4WD light comes on because it is switched by the front rod and the only way to tell is to see if it drives with the hubs out.
Attachments:
Last Edit: 19 Feb 2017 08:48 by Rick Whitworth.
The following user(s) said Thank You: OKAPETE

Please Log in or Create an account to join the conversation.

Powered by Kunena Forum