timing chain replacement

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mattv
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timing chain replacement

Post by mattv » Mon Sep 07, 2020 11:34 am

i'm preparing to replace the timing chain in 1980 j20. It was running good when the gasket failed. the cam gear is steel so maybe its been replaced already. its in perfect condition but the chain is kind of loose. if I replace the chain and keep the gears, which chain do I need? if I swap to a double roller chain do I have to change the gears?
will I need to upgrade the dist. gear? will a double roller fit inside the original timing cover?
why is my dogs nose always cold ?
thanks

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carnuck
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Re: timing chain replacement

Post by carnuck » Mon Sep 07, 2020 2:02 pm

Assuming 360, gears are different from double roller. Jeeps were mostly steel cam geared from the factory. I get the 3 keyway set to adjust cam timing. (Note: Don’t set a pre emissions cam for 5°timing advance or you get fast revs to 3,000 rpm with nothing after and major ping no matter what)
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Topic author
mattv
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Re: timing chain replacement

Post by mattv » Mon Sep 07, 2020 6:56 pm

thanks Carnuck
iv e read a lot of your posts and place much value on your opinion.
i plan to re-curve the dist. to get my advance in by 3k (it's a lot easier to adjust out the ping)
I thought I would leave the cam timing stock and as with many other parts I think its best to stay with stock parts whenever possible, such as timing chain cover, and chain sprockets.
my real concern is the dist. drive gear, since there were no problems i'd rather not mess with it
and would it be advisable to replace the chain and keep the old gears, or is that even possible?

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Stuka
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Re: timing chain replacement

Post by Stuka » Mon Sep 07, 2020 7:02 pm

I have never seen a replacement timing chain that doesn't come with gears. And since the gears wear into the chain, it would be best to replace them together.

No real point in a double roller chain with a stock engine. You are just increasing your cost.

As for the distributer, reuse the distributer gear on the cam. If you replace that gear, you have to replace the distributer gear too. You can keep your current distributer if you do so.

And your dog, its cold because its wet, evaporation cools it. Why is it wet? Because it increases their ability to smell.
1981 J10 AMC 258 with HEI and Weber 32/36 DGEV Carb, T176, NP208, D44/M23 with 4.56 gears and Detroit Locker, 6" lift, 33x12.50 Cooper STT's, BJ's Offroad Rear Dozer Bumper.
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Pevious Jeeps: 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ


Topic author
mattv
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Re: timing chain replacement

Post by mattv » Mon Sep 07, 2020 7:13 pm

thanks Stuka, that's a good point.
that's basically what I told my dog
"Arf" he said.


letank
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Re: timing chain replacement

Post by letank » Mon Sep 07, 2020 10:17 pm

the big issue with gears is the alignment of the oiling holes, it has been covered a lot, so for the ummmph time

timing gear oil slot

https://www.fsjnetwork.com/forum/viewtopic.php?t=12192

and add manifold vacuum timing

and ammeter bypass
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (227 Kmiles... the running test lab)
See Engine bits , Fuel and brake lines, Body work, Trany and TC


Topic author
mattv
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Re: timing chain replacement

Post by mattv » Tue Sep 15, 2020 10:11 am

thanks, I've already ditched the ammeter and upgraded to TFI ignition,
I went with a stock chain and gears ( from cloyes) and now I cant seem to get the cover aligned.
It seems I need to drop the oil pan to provide clearance ( because the oil seal wont compress enough to engage the dowel)
I've googled through all the jeep sites and everything I could find on AMC 360 and apparently no one else has encountered this problem
I'd rather not remove the pan and invest in exhaust work or pull the engine
any ideas would be greatly appreciated


Topic author
mattv
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Joined: Mon Nov 09, 2015 5:01 pm

Re: timing chain replacement

Post by mattv » Tue Sep 15, 2020 6:05 pm

so if I need to drop the pan I'll need to replace the gaskets. maybe I should pull the engine, rework the exhaust,replace the motor mounts, replace the shocks, and change the blinker fluid.
it was running good (with an oil leak) when I pulled it apart.
I've done engine swaps in plenty of Fords and Chevys but so far I'm not very impressed with the way this thing goes together.
I mean, the timing cover by itself is insane, not to mention the rubics cube power-steering-pump-braketry What the hell were they smoking?


letank
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Re: timing chain replacement

Post by letank » Tue Sep 15, 2020 6:11 pm

you have already removed the front oil pan bolts for the timing cover... yes it is a tight fit no need to remove the oil pan... there are 2 dowels that seem to mess up the alignment of the timing cover, the timing chain kit comes with the oil pan seal bits... you need to cut off the oil pan seal that are exposed and use the bits provided... then if it is too tight, smear enough silicone sealant...
Last time I did it -2 years ago- I ditch one of the dowels... yes it is a jeep... but at least the engine is better than a cheby or a ferd
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (227 Kmiles... the running test lab)
See Engine bits , Fuel and brake lines, Body work, Trany and TC


Topic author
mattv
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Joined: Mon Nov 09, 2015 5:01 pm

Re: timing chain replacement

Post by mattv » Tue Sep 15, 2020 6:50 pm

thanks Michel, that's very reassuring.
I pulled the lower right dowel (in accordance with the TSM) and was within mm s of aligning the remaining dowel ( with two of us horsing on it) while the front two pan bolts were loosely threaded and I thought it would slip in but "No" she cried and I prolly wrecked the gasket.
with your encouragement I'll try again, when I find a new gasket.


Topic author
mattv
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Joined: Mon Nov 09, 2015 5:01 pm

Re: timing chain replacement

Post by mattv » Wed Sep 16, 2020 4:58 am

By the way
Just HOW would you verify alignment of the oil passage in the cam gear?
Do I need to fill the pan and articulate the oil pump to observe the flow or is there a measurement?
Thanks


Topic author
mattv
Posts: 17
Joined: Mon Nov 09, 2015 5:01 pm

Re: timing chain replacement

Post by mattv » Wed Sep 16, 2020 9:37 am

I used a 5/32 drill bit
cut it down to about an inch and inserted into oil hole
then put tape on the back of the cam gear and slid it onto the shaft till the drill bit left a mark on the tape
I know, it's rather basic but kept it simple

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