Distributor - '79 Wagoneer w/360

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sansabarJ
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Joined: Sun Jun 16, 2019 1:40 pm

Re: Distributor - '79 Wagoneer w/360

Post by sansabarJ »

I have built ALOT of AMC V8s and 6 cylinders over 48 years of auto repair service and4x4 repairs and services . Been a auto repair facility for 40 years . Just some background experience I'm putting out here . Never once , never once ... have I had ANY cam gear or dist gear failures on any build . None . We here are having problems with offshore junk and incorrect gear manufacturing including these new China timing covers . In addition I have Noted the distributors may not be machined for proper gear mesh contact . I've been helping another member here on a DURASPARK vacuum can fail . We have found the Chinese NEW DURASPARK distributors are not machined the same externally as an OEM original DURASPARK unit . Quite a surprise to find the housing machining is not the same location as the original . I will advise everyone with fails to really consider buying a good set of OE gears . Yes even if they are used but in very good condition with no wear . Why ? Because tbey do not fail under all normal circumstances with correct OILING thru the cam gear , another major problem . I will recommend J&W JEEP Mark Duncan about buying a set or any other source for AMC JEEP engines and engine cores good for parts . Obviously don't buy worn gears that never saw an oil change . Another area for checking :
The timing cover absolutely must be checked for proper gear mesh . Do a test cover install with your dist using the yellow differential gear paste to get a good pattern . Grease won't do it .
Take it apart and note the gear mesh AND depth . How deep your dist gear engages the cam gear .
Well we know there has been a crap load of incorrectly machined gears from China along with those timing covers , and MSD CROWN and on these HEI units and others have had incorrectly made gears , including hardness issues so it is frustrating even for me to see this going on and not being resolved .
These HEI s are hit or miss as has been noted here. Some gears get torn up some not .
AMC is no different than a Buick or Ford or Chevy or dodge etc in the cam gear dist design as far as type of gears and how they work . There is not lining up of these gears BTW . Distributors get replaced all the time in vintage engines with no lining up dist gears and as soon as its running that's the end of any lining up you might have dealt with . So that idea needs to be put to rest .
OILING to the gears has been another problem as posted above . Check everything twice maybe 3 times , do a gear mesh test . Crown had impropertly machined timing covers and there's a good chance those are still out there in circulation. I highly recommend that you use your original dist gear on these HEI units . I do believe they can be swapped over . There are alot of threads on all of this and over on the AMC forums . Here we are though still having the trouble so I wanted to add my professional thoughts and to dings with experience on this subject .

SansabarJ
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Hobart
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Location: Chicago, IL

Re: Distributor - '79 Wagoneer w/360

Post by Hobart »

Thanks for all of the great info, Sansabar!
I've been searching a lot of posts here and at IFSJA, and learning a lot about the various things you mention above. My Wagoneer is fairly new to me, I've had it 7 months. Receipts indicate that the cam and distributor gears were changed by a previous mechanic during a bottom-end rebuild at about 80k miles. It looks like they thought the oil pump was locked up at that time, but it is unclear whether that was true or not. I bought it with 99k miles, and changed to an HEI after driving it about 400 miles. I put about 700 miles on it since swapping in the HEI until I burned up the cam-gear. So, my hope is that I made a blunder by not reusing the original (though it's not really original) distributor gear.
Going forward, I will check the timing gears and oil passages when I pull the front of the engine apart. The timing cover is an AMC unit. I'm somewhat sailing blindly, since I really don't know much more history on the engine. Hopefully I don't get bit again.

Thanks again.
Bill

1979 Wagoneer
1959 Bel Air
1968 Nova
1972 Eldo ragtop
1980 Z28

oregonphil
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Joined: Sat Oct 17, 2020 11:42 am
Location: Klamath Falls, Or.

Re: Distributor - '79 Wagoneer w/360

Post by oregonphil »

Yep, I tore up a distributor gear on a Mallory HEI some years ago. Right now my 401 is getting a rebuild and I had this set of expensive gears installed: https://teamgrandwagoneer.com/alfano-pe ... 1968-1991/
I will follow this up after I see how it goes.

OregonPhil
77sj 401 warmed over
72 Commando basically stock
07 Siena should last forever
76 FLH just for fun
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1978J10REDWHITE
Posts: 263
Joined: Fri Nov 20, 2020 7:25 pm

Re: Distributor - '79 Wagoneer w/360

Post by 1978J10REDWHITE »

oregonphil wrote: Mon Jan 18, 2021 8:24 pm Yep, I tore up a distributor gear on a Mallory HEI some years ago. Right now my 401 is getting a rebuild and I had this set of expensive gears installed: https://teamgrandwagoneer.com/alfano-pe ... 1968-1991/
I will follow this up after I see how it goes.

OregonPhil
Bit of a marathon post here.

I like this idea of these nickel/bronze material pieces, more $$ isn’t an issue with me.
It’s the satisfaction I know the best parts available without a doubt, are installed.
Read today VERY good point, that doing a dry check & Double check again, dry check after mounting the TC cover, verify the Dist., gear mesh “Depth” with that Yellow 'gear marking paint”, to verify the alignment.

This yellow paint for “gear mesh verify” task, for the extra little time assurance makes sense, to me it does anyway.
I looked and it seems the JEGS ($4.99) /Summit to order, local parts stores are a bust here this product!
Didn’t like the reports of the Prussian Blue stuff or GM product $35+ per container, was way more then necessary.

One other idea was to get several additional dist., gaskets to adjust depth if necessary.
Maybe another $5-6 for a few extra gaskets IF needed is on hand.

One last thing, what TC set do you plan on using and why?

There is so much info out there on this topic, I’m swimming in data overload about it.
I understand the alignment of oil slots on Top TC gear Must be correct with block/Cam outlet oil office.
If it is not aligned by Verifying it so, then the task of Cut-grind the proper path, to allow oil passage as OEM needs..
Got that point!
Along with the “excessive” oil grooves TC Top gear has too many slots causing cam gear oil starvation issues as per the forums I read .
Verify theses oil orifice alignments, oil delivery concerns , it is just common sense wisdom here.
Not a big deal Now I am aware , just Verify there points, and do what is necessary to correct!

Unless there is known a “known” proper OEM aligned set that addressed these specific points - issue, or partially so..
If so, let know what PN and brand is available, I will get that and be a little work ahead here.

Trying to figure this All out and do it methodically ONCE correctly.
Thx

letank
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Re: Distributor - '79 Wagoneer w/360

Post by letank »

Well, no financial interests here, I used bj's and checked the alignment with a nail. I never bothered with the yellow. BUT I reused the original distributor when I had to change the vacuum advance, the distributor from cardone was new , but with too many shortcuts for my taste. As Sansabar have said, get some OEM from the junkyard, or pay J&W for the real thing.
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)

oregonphil
Posts: 53
Joined: Sat Oct 17, 2020 11:42 am
Location: Klamath Falls, Or.

Re: Distributor - '79 Wagoneer w/360

Post by oregonphil »

Well, I can not really report back on how the timing/dist install was done because I did not do the work myself. Reused the cover that was there because it was still good. Timing gears were part of a set from Comp Cam https://www.compcams.com/high-energy-21 ... 0-401.html . I was not convinced that welding up the additional oil slots or any other oiling modification was necessary as this is not built for racing. Running good so far, but only have about 100 miles on it. It has got an exhaust manifold leak on the drivers side still to fix and then replace the rest of the exhaust system.
77sj 401 warmed over
72 Commando basically stock
07 Siena should last forever
76 FLH just for fun
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1978J10REDWHITE
Posts: 263
Joined: Fri Nov 20, 2020 7:25 pm

Re: Distributor - '79 Wagoneer w/360

Post by 1978J10REDWHITE »

Today found these little endoscopes for the cell phone - plugNplay cable and cam, that have reasonably good images with an LED backlight on them.
About $20 and I can get one, then when I swap-out the Dist to an HEI setup, can prime the oil pump with a drill.
And get a real time view of the oil that flows inside the TC, behind the Top Cam sprocket & near the Dist gear too.

This should give a little more knowledge here to us concerned on this specific topic.
Not sure when, yet likely this Spring should have a video of the machine..
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