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Questions about the NOS proportioning valve I bought?

Flatie46

Legacy Registered User
Gold Member
City
Russllville
State
TN
I bought this proportion valve for my '81 but their are some differences. The most noticeable is it's brass and on both '81 frames I have they are aluminum. Also the rear port seems bigger on the brass one. Anyone got any info on this? It was listed to fit my '81 not sure about the rear port part of it though? I've already bought new pre bent stainless brake lines, really was hoping for this puzzle to fit without adapting and modifying. ( that was pretty silly of me to think that)
 

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ag4ever

Average Nut
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City
Richmond
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TX
The NOS one looks like what I have on my ‘82 & ‘83.

You sure the ‘81 is aluminum, or just discolored?
 

Flatie46

Legacy Registered User
Gold Member
City
Russllville
State
TN
The NOS one looks like what I have on my ‘82 & ‘83.

You sure the ‘81 is aluminum, or just discolored?
I actually have two '81's still mounted on the frame and they are both Aluminum. I crawled under my '82 and had to dig a bit thru dirt and paint but it is Brass.
 

jerseyjeeps

Crazy about AMC Jeeps
Lifetime Member
City
Landing
State
NJ
I’ve taken apart over 100 CJs 76-86, with at least 80 of those being 82-86, but in even the early batch I’ve never seen an aluminum one. It doesn’t mean it didn’t happen tho. The 81-86 parts book would tell us if there was a difference. I’ll have a look if someone doesn’t beat me to it.
 

hefavitzen

Scrambler Junkie
BENEFACTOR
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City
Rock Hill
State
SC
Drum / Drum vs Disk / Drum?

Did the ‘81 have disks up front? I thought ‘76 was the Drum conversion year?
I have an 81 that has disks up front and drums in the rear (from factory). The front disks and calipers changed in style starting between the 1981 and the 1982 to 1986 CJ's.
 

ag4ever

Average Nut
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City
Richmond
State
TX
I wonder what the difference is in the valves. Material change for greater strength? :shrug:
 

spankrjs

Scrambler Junkie
Lifetime Member
SOA Member
City
Biloxi
State
MS
Both of my 1978 CJ-7's, disc/drum, had the smooth sided brass proportioning valves :shrug:
 

Flatie46

Legacy Registered User
Gold Member
City
Russllville
State
TN
I’ve taken apart over 100 CJs 76-86, with at least 80 of those being 82-86, but in even the early batch I’ve never seen an aluminum one. It doesn’t mean it didn’t happen tho. The 81-86 parts book would tell us if there was a difference. I’ll have a look if someone doesn’t beat me to it.
Like I mentioned before, both '81 Scrambler frames I have have Aluminum proportion valves on them. I know anything could be changed and anything is possible but one of them had been parked since the early '90's. I've pretty much confirmed it's under '80K miles. Plus you have to admit it's not a part that gets changed much. Either way I would like to confirm what was original. Also I appreciate your help with the research my friend.
 

Flatie46

Legacy Registered User
Gold Member
City
Russllville
State
TN
If it makes any difference the box has 2 part numbers on it. It has a sticker that says AMC 8983300004 then below it it says old part number3229568. I couldn't find much when I googled them, just thought it might mean something in a parts book.
 

Mancunian

Lifetime Member
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City
Bridgeport
State
WV
Would have thought that Alum valves would be subject to galvanic corrosion/too soft , but apparently they exist.
Given that possibility there may be no reason that Jeep bought valves from different suppliers to the same spec and that the bodies were different materials.
You should be able to buy a fitting to adapt the thread size at the rear.
 

Flatie46

Legacy Registered User
Gold Member
City
Russllville
State
TN
Would have thought that Alum valves would be subject to galvanic corrosion/too soft , but apparently they exist.
Given that possibility there may be no reason that Jeep bought valves from different suppliers to the same spec and that the bodies were different materials.
You should be able to buy a fitting to adapt the thread size at the rear.
I agree on the adapter I was just wondering if it was proportioned the same?
 

certifiablejeep

Definitley Certifiable
Lifetime Member
City
Bedford
State
NH
Not sure I have ever seen an aluminum one and I am in the boat with @jerseyjeeps with Jeeps torn down.
I am sure there were a few 81's in there... only real major difference that I noticed was on 76's, the prop valve was different as it was drum/drum... the shape is a little different and the proportioning also as you don't have the discs.

I will have to check my pile of prop valves... I know I have a lot of discolored brass ones, but I guess there might be an aluminum one... learn something new every day.

Was there a brass shortage in 81? Like times in history when other material were used? like steel nickels in 44-45?

cb
 

jerseyjeeps

Crazy about AMC Jeeps
Lifetime Member
City
Landing
State
NJ
Just checked the 74-80 Parts Book...the same one listed for 1981 above is also 79 and 80. ill grab a screen shot. Also for reference there is no difference in PB vs non PB in any of the listing in either books. Concensus might be growing that for some odd reason your two 1981 examples got changed out....another thought I had is even tho AMC was dumb in many ways, they wouldn't put a dissimilar metals thing going on on purpose..especially on a safety part. they would have had to put a plastic spacer or something between it and the frame bracket...
 

Flatie46

Legacy Registered User
Gold Member
City
Russllville
State
TN
Just checked the 74-80 Parts Book...the same one listed for 1981 above is also 79 and 80. ill grab a screen shot. Also for reference there is no difference in PB vs non PB in any of the listing in either books. Concensus might be growing that for some odd reason your two 1981 examples got changed out....another thought I had is even tho AMC was dumb in many ways, they wouldn't put a dissimilar metals thing going on on purpose..especially on a safety part. they would have had to put a plastic spacer or something between it and the frame bracket...
If I were to pull the one off one of the aluminum ones and it had the factory part number stamped into it would that prove it to be an original? Or could an aftermarket company use that part number also?
 

jerseyjeeps

Crazy about AMC Jeeps
Lifetime Member
City
Landing
State
NJ
If I were to pull the one off one of the aluminum ones and it had the factory part number stamped into it would that prove it to be an original? Or could an aftermarket company use that part number also?
Even the brass ones don’t have the part number. Does that one you have NOS have it? I still also need to run the long part number for you. 89 prefix tells me it’s late in the amc run.
 
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