Timing belt

Tiny
DEV123
  • MEMBER
  • 1996 CHRYSLER LHS

Replacing timing belt, found that both cam sprockets are 180 degrees out of position. Is there a reason someone would have done this, or is it just a mistake? I want to set the cams back to correct TDC position, but if they were set 180 deg out to solve a problem I should keep them as is. Thanks in advance for any help.
Tuesday, September 23rd, 2008 AT 2:39 PM

7 Replies

Tiny
DOCFIXIT
  • MECHANIC
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You sure engine was top dead center #1 cylinder? #1 needs to be up on compression stroke if you had it at top of exhaust stroke cam align makes would be pointing down 180 out. Pull #1 plug rotate engine put your finger in plug hole when you feel hear air rush out that is top dead com. Stroke. Everything should be aligned.
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Tuesday, September 23rd, 2008 AT 2:58 PM
Tiny
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Thanks for your reply Doc. I haven't checked the piston positions via plug sockets, will do tomorrow to confirm. But here are a few more details that will explain why I think the cams are 180 deg out:

I removed the timing belt cover and used a socket to turn the crankshaft sprocket until the alignment notch on the sprocket was in line with the TDC mark.

The timing belt was still on. The camshaft sprockets each have a punched alignment dot which at TDC should line up between two punched alignment dots that are above the camshaft sprockets, on the timing belt casing.

But when the crankshaft sprocket is at TDC, the camshaft sprocket alignment marks are not immediately below the casing dots, at the top of the sprocket. They're on the bottom of the sprocket.

My Haynes repair manual description and pictures show that the sprocket marks and casing marks should be beside each other when aligned, not separated by the diameter of the camshaft sprocket as they are on my engine.

Since all this is clear as mud, I'll try to post a picture asap. Thanks again for any and all replies to my question.
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Tuesday, September 23rd, 2008 AT 5:47 PM
Tiny
DOCFIXIT
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The crankshaft turns twice for one rotation of cam so you can have crank mark lined up but not on compression stroke of #1 your on the exhaust stroke.
4 stroke engine intake, compression,power and exhaust. WARNING you have an interference engine any rotation of crank or cam without belt on will result in valve damage.do not rotate the engine, put belt back on rotate crank 180 cam marks will move to top and you then can safely change belt. Trust me your engine is not 180 out, it wouldn't have run

Heres a link to the timing mark diagram

https://www.2carpros.com/diagrams/chrysler/lhs/1996
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Wednesday, September 24th, 2008 AT 11:34 AM
Tiny
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That's the explanation I needed, I knew I was missing something simple. Thanks Doc.
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Wednesday, September 24th, 2008 AT 12:21 PM
Tiny
DOCFIXIT
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You are very welcome I would have felt badly if you would have damaged the valves costing $$$ which none of us have much of these days.
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Wednesday, September 24th, 2008 AT 1:14 PM
Tiny
MABDULAHI
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  • 2 POSTS
  • 1999 CHRYSLER LHS
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 124,000 MILES
What happen is all the sudden I notice my car overheated. At that time it was starting well. When I start the car it runs and I hear a griding noice over by the water bumb. I open the timing belt cover plate and found that the Idler pulley bearings are all out. I got new pulley and replaced it. The water bumb was ok was not leaking at all. I pul the timing belt back on the pully and the water bumb and put everything back together I tried to start the car. All it does is crank not turning over. I notice I did not align the Crank Shaft and the Cam to the proper places. Open it back and turn the crank shaft to the point where it supposed to same as the camshaft. Ever since then I can't start my car I am not sure if I am way off the timings of the crank and cam. Please point me to the steps I need to do to get it fixes. I would really appreciated. Thank You very Much.
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Friday, November 30th, 2018 AT 8:38 AM (Merged)
Tiny
BMRFIXIT
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Hope that help
let me know


https://www.2carpros.com/forum/automotive_pictures/99387_35_2.jpg

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Friday, November 30th, 2018 AT 8:38 AM (Merged)

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