Exhaust system...

Roberto Flores · Post by **Roberto Flores** » Sat Dec 15, 2007 12:59 pm

Dear fellows:

I would like to know if the exhaust system of Willys jeep models CJ2A, CJ3A and CJ3B is the same.

Many thanks in advance,

p3ferris · Post by **p3ferris** » Sat Dec 15, 2007 2:32 pm

I do not know about the 3a and 3b but the cj2a has 2 different exhaust systems and I have seen a third but do not know if it is stock. First one is straight back second takes it to the right side. The third goes out the left side behind the back tire. This is the one that I do not know if it is stock.

petesilfven · Post by **petesilfven** » Sat Dec 15, 2007 3:09 pm

The Walker catalog lists the same system for all of the jeeps you mention except for CJ2A before ser# 18638. It fits CJ5 as well.

front pipe - 42287

intermediate pipe - 45095

muffler - 21012

tail pipe - 42006

This is the best system available. I bought one from my local auto parts dealer.

lowenuf · Post by **lowenuf** » Sat Dec 15, 2007 4:02 pm

pete...was there a part number from walker for the one before #18638? that is the one i need...thx..low

Steve Webb · Post by **Steve Webb** » Sun Dec 16, 2007 5:14 am

Do not buy any of the muffler kits, they are garbage. I am stuck with one for now but right before I put my tub on I will change to the Walker stuff.

petesilfven · Post by **petesilfven** » Sun Dec 16, 2007 8:44 am

lowenuf wrote:pete...was there a part number from walker for the one before #18638? that is the one i need...thx..low

Walker doesn't list the early system. I imagine the later one would work, unless you're a stickler for originality. Walker systems are really nice. They are made of aluminized steel, and they fit, unlike a lot of the foreign made junk on the market today.

lowenuf · Post by **lowenuf** » Sun Dec 16, 2007 1:06 pm

petesilfven wrote:
lowenuf wrote:pete...was there a part number from walker for the one before #18638? that is the one i need...thx..low

Walker doesn't list the early system. I imagine the later one would work, unless you're a stickler for originality. Walker systems are really nice. They are made of aluminized steel, and they fit, unlike a lot of the foreign made junk on the market today.[/quot

yup, i am, i am totally restoring to as original as i possibly can, a 1945 CJ2A...low

Cuz · Post by **Cuz** » Sun Dec 16, 2007 2:45 pm

This is all Walker offers.

The early CJ2A used a system very similar to the late WWII MB. The muffler was hung diagonally at the rear and all the parts were (when comparing 49 Willys Master Parts with ORD 9 G503 1949) essentially the same as the MB except the shape of the exhaust head pipe and extension pipe which had to clear a different tranny crossmember.

So for Low the hard to find parts are the front exhaust pipe A-10199 and the extension pipe which didn't have a number listed in the 49 Willys book

You can download a full size version of this photo here:
http://img.mypicgallery.com/willyscjpar ... ations.jpg

lowenuf · Post by **lowenuf** » Sun Dec 16, 2007 3:46 pm

so i guess my ONLY option IS the repro suppliers....thx

Sean Collins · Post by **Sean Collins** » Mon Dec 17, 2007 8:02 am

Wes:

The early CJ2A used a system very similar to the late WWII MB. The muffler was hung diagonally at the rear

Beg to differ.

The early CJ2A (up to s/n 18638) used the same passenger side muffler as earlier MB. No Willys parts list after '45 depicts the early CJ2A setup.

Sean

p3ferris · Post by **p3ferris** » Mon Dec 17, 2007 11:36 am

I am not sure what exactually you guys are talking about on the muffler but mine is a 48 serial# 183215 and it has the muffler that goes across the backto the passengers side from the drivers side. I believe with the pto it makes a difference. It looks like the pipe that cuz has pictured on top in pieces. If this helps any.

lowenuf · Post by **lowenuf** » Mon Dec 17, 2007 2:35 pm

p3ferris wrote:I am not sure what exactually you guys are talking about on the muffler but mine is a 48 serial# 183215 and it has the muffler that goes across the backto the passengers side from the drivers side. I believe with the pto it makes a difference. It looks like the pipe that cuz has pictured on top in pieces. If this helps any.

on ALL 1945 CJ2A's, and ONLY 1946 CJ2A's up to serial number 18638, used a long oval muffler, mounted underneath the passenger side seat, and the pipe tip exited in front of the right rear tire just like the end of the war MB's...

after serial number 18638, the exhaust system was changed to the style Cuz shows, with the exception that they never used the "angled" position, only one parallel to the rear differential, and yes, the PTO made a difference, and that difference was in the length of the muffler, if a PTO was used, it required the short round muffler for the PTO driveshaft to clear the muffler, otherwise, the longer muffler was in the way of the PTO driveshaft aligning with the rear gearbox.

low

p3ferris · Post by **p3ferris** » Tue Dec 18, 2007 5:35 am

Thanks for the info low

Cuz · Post by **Cuz** » Tue Dec 18, 2007 8:16 am

Ed,
I try to avoid the use of the terms like "Always, Only, Never" since these are very finite and are often proven incorrect with deeper research. This is especially true of the smaller vehicle manufacturers who often had to make do with what was available. Production line deviations are quite common. Sean provided me with some interesting parts illustrations which make the liklyhood of the angled rear frame muffler being used very slim. As with most production info from Willys there are many open questions remaining.
The WWII MA, MB's used several different systems including both round and oval ufflers and both ahead and behind the rear axle outlets. The diagonal system above was the G503 Parts list "deep mud system". The A6118 oval muffler, the A1146 round muffler and the A9090A round rear muffler were all listed for the WWII MB. The A1168 oval muffler is listed in the 45 CJ2A parts list. The A9090 round muffler is listed in the 49 Master parts list for the CJ2A up to SN 18638 and muffler 641878 is listed there for those 2A's after SN 18638. Exhaust system mountings found on period CJ's helps with researching this issue but ultimately we need to find the factory drawings and production line change notices to be absolutely sure.

Sean's data makes a very good argument for at least early 45's having a right side tub mounted muffler exiting ahead of the rear axle but I think he'll agree that this is NOT absolute proof that ALL 45 and earl 46's had this system.

This is Sean's photo from the 45 Salesman's Manual.

He has posted two 1945 1st ed 2A parts and 45 2A maint pages as well.
http://www.cj-2a.com/parts/exhaust/muffler_parts.pdf
http://www.cj-2a.com/parts/exhaust/muffler_maint.pdf

Sean Collins · Post by **Sean Collins** » Tue Dec 18, 2007 11:26 am

Wes:

I try to avoid the use of the terms like "Always, Only, Never"

hear, hear! I have learned the same.

The A1168 oval muffler is listed in the 45 CJ2A parts list. The A9090 round muffler is listed in the 49 Master parts list for the CJ2A up to SN 18638

I would caution against using later parts lists as an indication of what was originally used on a vehicle at the time it was produced.

The parts lists show only what is available for purchase at the time of publication, so many original production parts have been purged and/or superceded in later manuals. Even the '49 CJ2A specific parts list no longer shows some of the parts originally used on a '45, '46 or '47

The A-9090 muffler is not listed any of the 3 CJ2A specific parts lists. I suspect it would fit in place of the A-1168, so was simply offered as a viable replacement in the master list.

The "45-49" master parts list (2nd. edition, pub. 1955), has eliminated both the A-1168 and A-9090 mufflers, and replaced them with # 809480.

Is is for this reason that I've come to regard only the 3 period correct CJ2A specific parts lists as the most valid wrt what was originally used.

Sean's data makes a very good argument for at least early 45's having a right side tub mounted muffler exiting ahead of the rear axle but I think he'll agree that this is NOT absolute proof that ALL 45 and earl 46's had this system.

Agreed. Nothing is ever certain wrt what Willys did or might have done.

But there is evidence to suggest the passenger side muffler was the "usual" location up to s/n 18638, aside from it being the only one shown in the parts list.

A number of '45 & early '46 CJ2A have been found of late, which still have complete or partial mufflers on the passenger side. My own '46 #16279, while it had been updated to rear mount, still had remnants of hanger attached to the tub brackets.

TTBOMK, no one has yet found a "deep mud" transverse muffler. If one is ever found, then we'll know for sure.

A couple of driver-side mufflers have been found, but it's believed these are special adaptations to provide clearance for some aftermarket add-on implement. A front PTO shaft runs along the left side of the engine, and might likely have an interference problem w/the stock early exhaust pipe, so the muffler was moved. But there are no factory muffler mount brackets on the left side of the tub.

We may never know for sure, but the preponderance of evidence suggests only 2 original "standard" locations and types of muffler.

Sean

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