Transfer box converison NP241 to NP242 - permanent allrad

[Bundas]

Hallo,

This topic is started in the Search gear forum but I thought it's better if I open a new one here..

Sorry for writing in English but my German is terrible and I don't really want to miss out any info.

I understand and read and translated with google the relevant article from the wiki, however that was a conversion for 208 to 242. Does anyone has some experience with conversion from 241 to 242 - my LT is from 1995.

Until now my biggest problem - based on the Haswenwerk threads - was that I thought it can't be sorted to have all 5 positions on the transfer case but seems by the wiki and Josef confirmed that it's possible with the shorter selector lever.

Can somebody tell me what parts do I need for this conversion and where to start - which 242 box is the ideal one?

Many Thanks

Andras

[Waldfahrer]

I copy my answer from the search thread as starting point for a possible discussion:

But keep in mind Andras, the shift 241 -> 242 is a little bit more tricky as from 208!
You have to disassemble both and put the input shaft from the 241 to the 242 additionally to the steps described in the wiki!
Also, i think the mount bolt pattern of the both TC's is rotated a bit. Have you the TC holder with both bolt hole pattern already drilled?

what parts do I need for this conversion

I think, if you go with the TC from the wiki (Jeep 4l engine), there are no more parts necessary than these described there (SYE-Kit, Inter-Flange)!

See also the discussion here: viewtopic.php?f=95&t=11401

Maybe you can contact sven strumann here in this forum, he had done this conversion!

Josef

[Bundas]

I think I start to understand the whole thing browsing the forum, wiki and the Hasenwerk page as well. What is still a bit unclear and probably just David shows it to look easy (as he was converting from 241 as well) that he only had to swap the front flanges while you said the whole input shaft needs to be transferred from the 241 to the 242 box. Sven Strumann's relevant comment on the other thread you linked above also a bit unclear (the language barrier and google translator combo not helping..)

[Waldfahrer]

Hi Andras,

the problem seems to be the input shaft: The "VW" 241 has a short shaft, where the flange is slide on and fixed with a center nut.
Lower pic here: viewtopic.php?f=95&t=11401&p=55659#p55659
On this pic you can also see the TC-Holder with both drill patterns!

The 242 has a hollow input shaft (upper pic), so the flange of the VW 241 cannot be mounted!

I was not able to clarify, if the input shaft of the 241 is a separate part and similar to the 208 only glued into the (hollow) shaft, or if it is a special part, only made for VW. The other forum members think, the second possibility is true.

But I never had a 241 input shaft to see by myself

Josef

[Bundas]

Hi,

Well I am starting to be the nightmare of all UK scrapyards to get a transfer case.

It seems that I have located one but before buying it I'd like someone to confirm it for me if I buy the right one:

It's coming from a Jeep Cherokee XJ pre 1996 with a 4.0 Petrol engine and the badge is 242J.

Could that happen that it won't match with something or it should be OK?

Many Thanks

Andras

[Waldfahrer]

Hi Andras,

It's coming from a Jeep Cherokee XJ pre 1996 with a 4.0 Petrol engine and the badge is 242J.

Sounds good, does it look like the TC on the enclosed Pic (bottom view, rear output down)?
See the long tail slip-yoke-housing!

Then, important, like mentioned in the Wiki - the spline count:
23 Input shaft (hollow)
27 rear output shaft
32 Front output shaft
and Mech Speedo drive.

Then again, you need the Rubicon Express kit 1801, and a self-made interflange!

Hope you have the capabilities - eg. access to a lathe or anybody who can make the modifications for you!

Good luck, Josef

[Bundas]

HI Josef,

Unfortunately it's about 300 miles away from me so don't really have the chance to look at it but should be ok.

Do you know any European company who sells the Rubicon express SYE kit or I need to go to the US and importing route?

Andras

[HelmutJ]

Hi Andras,

you should look for sellers for Jeep Offroad-Parts like this http://www.fte.co.uk/ and ask them. I'll buy mine now by this dealer http://www.rsl-offroad.de/

greets
Helmut

[Bundas]

Hi Helmut,

Thanks a lot, I have sent them an email already, I was just thoght you might know a dealer with a webshop or something to buy directly.

Josef,

I actually have a very good facilty for lathe and materials at my work so it shouldn't be a problem with the drawings from the Wiki. I actually considering to get the cap (the red one) turned as well to save some money.. Only external work is that I need to get the shift leaver laser cutted with someone.

Once it's done, next project are Unimog wheels.. Keep you posted.

[Waldfahrer]

know a dealer with a webshop

Here: http://www.4x4garage.de/index.php?route ... ct_id=5105

But it's normally no problem to buy directly in US!

shift leaver laser cutted

I made mine old-fashioned with a file

Please document how you deal with the input shaft, maybe we can add this to the wiki!

Greets Josef

[Bundas]

Thanks for the link, that's quite expensive this way... I will definitely turn here as much as I can. Price of a TC is £100.. 2 years ago before I moved to the UK I would do it with a file myself but laser cutting is so common here that now I have to go for it as I finally have a chance to try.

[Bundas]

Hello Everyone,

Long time I posted the last thing about this conversion but I am nearly finished now.

It took months to get all the parts done, buy shipped etc. but seems all with me and all the internal parts being transplanted. When we were putting it together today we came through a very serious issue and don't know if any of you had it before or I am the first one:

The front output flange doesn't slides on the 242 box output shaft as the splines are deeper - it's still has 32 teeth as originally discussed..

Does any of you have idea for the solution or shall I just give it up now and scrap everything after I invested a lot of money in this conversion. Getting seriously disappointed now.

Thanks a lot

Andras

[Waldfahrer]

Hi Andras,

don't give up!
What 242 do you have? The front output shaft of the 242J should fit!
If your shaft really doesn't fit, I think you can replace it from another 242J, from a junkyard (took your flange with you).
Or buy the shaft alone anywhere in the USA, there are lots of providers.
I haved ordered the main shaft alone at cobra transmission to convert a new (short) to the older version with long main shaft.

Give me the measures of your shaft, outer and inner diam of the splines, so I could compare them with mine!

Greets Josef

[Bundas]

Hi Josef,

I have a 242J with 32 splines on the front output shaft so just as it was told in the Wiki

However it seems that there is a slight difference between the shape of the teeth between the 241 and 242 shafts/flanges. - See the photo:

While the 242 yoke (left on photo) teeth are a bit more pointed the the 241 teeth are more square (right). Interestingly the 242 yoke slides on the shaft of the 241 but not the other way around. I identified 3 possible solutions:

First: Swap the front output shaft with the cogwheel from the 241 into the 242
Second: Swap only the shaft from the 241 to the 242 and put the 242 cogwheel on it - hope it's the same
Third: Grind off the "points" from the splines on the 242 shaft - that's the least I want but I think we only talking about 0.1 mm so it's not a structural mod, but could effect the hardened surface and don't really want to get it hardened again.

Unfortunately my man who does the gearboxes is not open today so can only continue on Monday but keep you posted. Just for the Wiki record the 241 to 242 swap of the input shaft is a straightforward thing: take the snap rings off both in the inside which holds the gears in place to the housing and just change them.

Andras

[Waldfahrer]

Hi Andras,

unfortunately I can't see the pic but you mentioned all solutions already!
Even grinding down the shaft on a lathe should be possible without problems: the hardening is deeper than 0.1 mm.
See the pic of a shortened shaft; the hardening zone clearly can be seen.
Additionally, it is not obligatory necessary because the shaft/flange have no relative movement if mounted!

Greets Josef

[Bundas]

Hi Josef,

Unfortunately I can't see your picture now :). International picture posting is not working great...

In this instance I might go for the grinding option; it shouldn't be too difficult (just hard..). Anyway I will see tomorrow if the front output shafts are interchangeable between the 241 and the 242.

As with the topic do you think that the 241 (or 208) mechanical speedo sensor is a straight swap between the 242 as the one I have on that is electronic. I have managed to change the wheels on the shafts so that's not an issue.

Andras

[Waldfahrer]

Unfortunately I can't see your picture now :)

Odd
But you can see the pic also in the Wiki article, it's pic No. 5!
The hardening zone is about 1 mm deep, and includes the whole spline teeth.

do you think that the 241 (or 208) mechanical speedo sensor is a straight swap

If you have the big sensor hole in the rear housing of the TC where the speedo is fitted, as shown in pic 7 in the Wiki article, then it should be a straight forward issue!

Josef

[Bundas]

So the transferbox is now done and running as it should be. Issue was the different shape of of the splines I mentioned above. Solution was to swap the shaft only as the cogwheel which is driven by the chain is not identical in the 241 and the 242 but the shaft are interchangeable.

Managed to swap the small plastic wheels on the end of the speedo sensor as well, so it's working now but won't say too accurate. I have one with 35 teeth now and it's still too small. How many teeth drives do you use on yours? - I read a couple of Jeep sites and it seems that for our differential ration and my wheel size (10.5r20) I need to have 41 teeth. This is the same as how you adjust your speedo or you just get it recalibrated?

Thanks

Andras

[Waldfahrer]

Hi Andras,

So the transferbox is now done and running as it should be.

Nice to hear Did you made some pics to add some to the wiki?

I read a couple of Jeep sites and it seems that for our differential ration and my wheel size (10.5r20) I need to have 41 teeth.

The Jeep site will not really help you, because it's also depending on the VW- speedometer rpm/speed - ratio!

my wheel size (10.5r20)

I have 31 teeth with the standard wheels 225/75R17.5 (Diam about 800mm). So if you have tires with bigger Diam, you will need a speed gear with fewer teeth then the 31: found D=950mm for your 10.5R20 so you will need 800/950x31 = 26 teeth!

Don't know if availabe - otherwise you have to adapt the speedo gear midst the two speedo-cables!

Another factor to take into account is the teeth-count on the both main-shafts, but they should be the same?!

Greets Josef

[Bundas]

I knew it can't work by the first attempt..

I did a little test drive today and started to smell some burnt oil so checked the transfer case if it leaks anywhere and after a bit of thinking I found the mistake: I haven't put any RTV or sealant on the washer of the RE flange so I think the splines carry a little bit of oil out and it's dripping between the alloy spacer and the RE flange - I should have read that wiki article with someone who speaks German not just translate with Google and miss that pretty important line...

Correct me if I am wrong but I can't think of anything else as an issue as it's nice and dry everywhere else.

On the bright side every gear works just fine, lever is ok as well and most importantly no stupid noises anymore (from the Transfer case at least..)

Oh and by the way on test trip I was testing the diff locks as well and the front is fine but the rear one is stuck - of course in the locked position - so it was not a great drive home after.

Any ideas where I could get some parts for my rear diff in case I need to rebuild it? - Couldn't find the parts on classic parts or ebay.

Thanks

Andras

[Waldfahrer]

Hi Andras

I haven't put any RTV or sealant on the washer of the RE flange so I think the splines carry a little bit of oil out and it's dripping between the alloy spacer and the RE flange

Annother point I should add to the wiki - I made a custom, thicker washer, fitting at zero clearance between the RE-flange-body and the snap ring.
So the flange can not sway on the main shaft! Otherwise the sealant will break again!
This assembly is now dry since 15000 km.

the rear one is stuck - of course in the locked position

Then you can hope that only the leverage ist stuck - you shold try to move the bellows back and apply some M0S2 Oil.

There are almost no parts of the diff lock available as new spare parts, only maybe used parts from forum members I think!

Greets Josef