Thank you for letting me join the forum. It is always nice to learn from others.

I have a 2001 WJ with the V8. I recently broke the 247 transfer box when I successfully pulled a huge lorry out of the mud.

I decided to change the 247 to a 242HD - and that is installed in the car with the new drive shafts. The front drive shaft now has a UJ on the diff and a cardan at the transfer box end. Where I am stuck is that I don't have and cannot find the four special bolts that couple the cardan to the box. Can anyone help? Part numbers? Grateful as ever for any contributions

 

Welcome to CF!

Okay, here's what I found at moparpartsoverstock.com

BOLT.mounting. .312-24 X 1.170 (5/16-24 X 1-3/16)

Mopar part numbers; $3.94 USD each
06036415AA
06033363
06033434
06033893
06034966
06036147AA

All of these are the same but have different numbers because of manufacture date and model application, such as Dodge, Chrysler, Jeep etc.

 

You are a genius. I have spent hours trying to find an exploded diagram like these. One question though - with the 242HD the bolts point backwards with the thread in the transfer box yoke. The drawing I am looking at shows the cardan with bolts and saddles. Am I being stupid?

 

You are right. All the bolts on my WJ are metric - so I found a tap that fitted - or so I thought - and it was metric 7x1. The link you sent me actually lists the part number of the front drive shaft P52853500AA - so I am sure they are the correct bolt. But, note they are 5/16 -24. They are imperial because New Process or New Venture never tooled metric. It's just amazing how the more you understand - the less you know about. p.s. This site came through brilliantly - another big .com hasn't replied to my question.

 

Bloody Hell! I just accidentally hit the "ALT" key and lost a long post!

Anyway, New Process and New Venture are the same plant and were located here in Syracuse, NY. NP was owned by Chrysler and NV was owned by the employees. As far as I know, everything was threaded Imperial. At least all the driveline parts are. I've been wrong before, so before you run that metric tap thru the flange yoke, make sure a 5/16 fine bolt doesn't fix.

The NP/NV transfer case was a new innovation in the industry when it first hit the market. It was the first aluminum case, chain drive unit that stood up to the torque of a V8 very well and everybody wanted it in their trucks. The 242 is rated at about 1500 lb/ft torque capacity, but remember lower gears increase the torque. I think the 231 is the strongest of the jeep lineup. I have the 242LD in my 2000 4.0 and have had ZERO problems with it.

 

Just to finish the tale, given I couldn't identify the bolts, I tried my taps by hand to determine the thred. The m7 went in without difficulty. It was a bit loose at the begining but seemed ok. I used ebay to buy some titanium cap head M7 bolts (they are used on BMWs and Mercs as well), and they went in ok but slipped in the thread. No damage has been done. Following your reply, I have since tried the 5/16-24, which is a much better fit. It's ages since I played with UNC and UNF threads - that's why I didn't twig it! I should be shot - professional engineer and all!
Anyway, bolts on order and maybe it will move again.
p.s. This engine is now on 184k and has run on LPG since 2003. I had to replace the heads last year at 176K. That speaks volumes about quality of valve seat steel.
First post and total result. Fantastic and thank you

 

Well professional engineer, meet professional toolmaker! At least you guys finally did away with the damned Whitworth! Or have you?

I'm not trying to puff up your ego, but something in your first post told me you were more intelligent than most newbies here.

I'm not going to crawl under my jeep out of curiosity, but I believe those are double-hex head bolts, right? Ones that need a 12-point socket or wrench? I think they are ANSI grade 12, but grade 8 is good enough, unless you're going to keep pulling lorries out of the mud! Somewhere on this site is a video of a Cherokee pulling a loaded 18-wheel moving company truck out of a snowbank!

 

Well there you are then! Takes one to know one!
I'll probably get banned for this because it is off topic - but maybe one little indiscretion - I am actually a Fellow in that famous Institute on the Strand in which Faraday was a Fellow - and I achieved it by being the first in the world to automatically examine the quality of production banknotes at a facility run by a famous Canadian. Cannot say more. I also own two other patents in the design and detection of security threads in Banknotes - given all this falls under the remit of Electrical Engineering and haven't done bad upgrading the 247 to the 242HD as a token spannerhead! p.s. Did you know that it is used in the Hummer? Thanks again. If ever you are in France you must look me up!

 

Look for a Private Message.

 

Dang, just when it was getting good!

 

Oh posh! Send him a PM yourself! I just thought I'd keep it "on topic."

BTW, once you understand and get used to working with metrics, they are SO much easier to work with.

 

Ah the old MKS system. How I recall working with the acceleration due to gravity figures of 9.82 m/s2 vs. 32ft./sec.2

 

I'm a retired toolmaker and besides learning it in school, I had to build plastic molds for LeGrand, a french electrical manufacturer, while I worked for Pass&Seymour. Metric thread is easy to understand, but length dimensions take conversion or metric measuring devices. Usually conversion because we were using American milling machines. When using automated mills (CNC), the computer does the driving.

I agree when it comes to things like newtons, pascals. lumens, bar, etc it gets confusing as hell. BTW, the conversion factor mm to inch is .03925. To figure tap drill sizes for metric thread you take the OD and subtract the pitch, as in distance between threads. THEN you have to find the closest US Standard drill size to your calculated metric drill. (unless you have metric drills)