Pondering Timing Chain replacement

Heinz I have about 78,000 miles on my coach and am having the same thoughts
as you are. When I replace the cylinder heads this summer will also replace
the timing chain and sprockets. Everyone one I have ever talked to(including
Joe Mondello) says that the Cloyes double roller chain and heat treated
sprockets are the best on the market. Best price I have found for them is
at Summit, part # CLO-9-3113 for $78.95, or from Mondello part # TR252 for
$89. Nice thing about the cloyes double roller chain and sprocket is that
it has three positions for timing it either standard or 4 dgrees retarded or
advanced. Mondello even sells a CB-15 off set cam bushing for perfect
degreeing.

A word of caution when replacing the timing chain and sprockets. If you
have a rebuilt engine and the rebuilder honed the main bearing saddles, you
may need an undersized timing chain. I don't know if under size timing
chains are marked or not. In fact never knew there was such a thing until I
read Mondellos technical book. The only way to tell positively is to
measure between the front cam bearing and the front main bearing housing
bore, it should be 2.424" with the cam bearing in place. If its less you
need an under size chain. Mondello has them. They could also probably tell
you how to be certain what you need.

>As I now have about 100k+ on the 2nd engine and the first one w.ent at
135-ish with timing chain failure being a contributing factor (so I was told
:-) I'm contemplating changing the timing chain, water pump and whatever
else is up there when I get home from this trip.
>
>I've been trying to collect info and wisdom from some of my customers (who
are in automotive) to get opinions as to whether to or not to. Feedback was
mixed to say the least and ranged from shoulda already to if it ain't broke...
>
>However, based on the past experience I'm planning to go ahead anyways. Now
the quander and question... where to get the timing chain and what is the
variety that will give me most service and peace of mind?
>
>Cinnebar? Mondello? Jim Bounds... you jump right on in here please :-)
>
>I actually think I have one that originated at Clasco years back, but I'd
rather get new and have a better chance that I only have to do it once.
>
>At the same time I'm going to try and find a waterpump that was built for
reverse rotation, i.e. serpentine setup, though I've not had cooling
problems until yesterday when the fanclutch said bye-bye.
>
>Are there any high milagers out there that have changed timing chain and
are there some that wish they had?
>
>Any and all thoughts welcomed.
>
>TIA - Heinz
>
>P.S. Any other related stuff that I should be considering while up there
digging around the front?
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
"The beautiful Mohawk Vally"
 
Something I forgot to add Heinz. I would and am going to also install
Mondellos camshaft thrust button and bolt to eliminate camshaft walk and
wear of the timing chain and reduces timing problems. It is part # TB745
and is $18. Be sure if you order it you tell them that the cam is still in
the engine.

>Heinz --
>
>I changed to a Cloyes on our GMC, I got it from Chuck Stoddard because I
>couldn't find the same model anywhere else.
>
>It was the 'middle' chain, a true roller chain. They make a 'standard',=
this
>one, which I'd recommend called 'heavy duty' and an 'extra heavy duty'. I
>don't have the part number, but I'm sure someone will post it if someone
>else doesn't.
>
>Personally, I think the cost of changing a chain is cheap insurance, and
>have changed them on many high mile vehicles. It isn't expensive, actually
>cheaper in the long run since you get better valve timing, engine
>performance and economy.
>
>I don't know if the 455 is an interference engine that is, improper valve
>timing could let the valves kiss the piston tops. I do know that you won't
>get far if the chain gets loose enough that it jumps a tooth. Been there,
>done that with a 301 cube Pontiac. Not recommended.
>
>That's my 2=A2 worth.
>
>Mark
>
>> -----Original Message-----
>> From: owner-gmcmotorhome
>> [mailto:owner-gmcmotorhome]On Behalf Of
>> heinz
>> Sent: Saturday, May 01, 1999 2:16 PM
>> To: gmcmotorhome
>> Subject: GMC: Pondering Timing Chain replacement
>>
>>
>> As I now have about 100k+ on the 2nd engine and the first one
>> w.ent at 135-ish with timing chain failure being a contributing
>> factor (so I was told :-) I'm contemplating changing the timing
>> chain, water pump and whatever else is up there when I get home
>> from this trip.
>>
>> I've been trying to collect info and wisdom from some of my
>> customers (who are in automotive) to get opinions as to whether
>> to or not to. Feedback was mixed to say the least and ranged from
>> shoulda already to if it ain't broke...
>>
>> However, based on the past experience I'm planning to go ahead
>> anyways. Now the quander and question... where to get the timing
>> chain and what is the variety that will give me most service and
>> peace of mind?
>>
>> Cinnebar? Mondello? Jim Bounds... you jump right on in here please :-)
>>
>> I actually think I have one that originated at Clasco years back,
>> but I'd rather get new and have a better chance that I only have
>> to do it once.
>>
>> At the same time I'm going to try and find a waterpump that was
>> built for reverse rotation, i.e. serpentine setup, though I've
>> not had cooling problems until yesterday when the fanclutch said bye-bye.
>>
>> Are there any high milagers out there that have changed timing
>> chain and are there some that wish they had?
>>
>> Any and all thoughts welcomed.
>>
>> TIA - Heinz
>>
>> P.S. Any other related stuff that I should be considering while
>> up there digging around the front?
>>
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
"The beautiful Mohawk Vally"
 
Heinz are you using 1-888-666-3355? Mondello also has a web page that you
can order on.

>Thanks Thomas,
>I called Mondello the other day but gave up holding :-)
>I was going to order the book and catalog as a starter but it sounds like
>you have the research already done. Thank You :-) I'll try to get my order
>in on Monday so that the stuff be home by the time I am.
>
>Heinz
>
>
>
>Something I forgot to add Heinz. I would and am going to also install
>Mondellos camshaft thrust button and bolt to eliminate camshaft walk and
>wear of the timing chain and reduces timing problems. It is part # TB745
>and is $18. Be sure if you order it you tell them that the cam is still in
>the engine.
>
>
>
>
>

>>Heinz --
>>
>>I changed to a Cloyes on our GMC, I got it from Chuck Stoddard because I
>>couldn't find the same model anywhere else.
>>
>>It was the 'middle' chain, a true roller chain. They make a 'standard',
>this
>>one, which I'd recommend called 'heavy duty' and an 'extra heavy duty'. I
>>don't have the part number, but I'm sure someone will post it if someone
>>else doesn't.
>>
>>Personally, I think the cost of changing a chain is cheap insurance, and
>>have changed them on many high mile vehicles. It isn't expensive, actually
>>cheaper in the long run since you get better valve timing, engine
>>performance and economy.
>>
>>I don't know if the 455 is an interference engine that is, improper valve
>>timing could let the valves kiss the piston tops. I do know that you won't
>>get far if the chain gets loose enough that it jumps a tooth. Been there,
>>done that with a 301 cube Pontiac. Not recommended.
>>
>>That's my 2=A2 worth.
>>
>>Mark
>>
>>> -----Original Message-----
>>> From: owner-gmcmotorhome
>>> [mailto:owner-gmcmotorhome]On Behalf Of
>>> heinz
>>> Sent: Saturday, May 01, 1999 2:16 PM
>>> To: gmcmotorhome
>>> Subject: GMC: Pondering Timing Chain replacement
>>>
>>>
>>> As I now have about 100k+ on the 2nd engine and the first one
>>> w.ent at 135-ish with timing chain failure being a contributing
>>> factor (so I was told :-) I'm contemplating changing the timing
>>> chain, water pump and whatever else is up there when I get home
>>> from this trip.
>>>
>>> I've been trying to collect info and wisdom from some of my
>>> customers (who are in automotive) to get opinions as to whether
>>> to or not to. Feedback was mixed to say the least and ranged from
>>> shoulda already to if it ain't broke...
>>>
>>> However, based on the past experience I'm planning to go ahead
>>> anyways. Now the quander and question... where to get the timing
>>> chain and what is the variety that will give me most service and
>>> peace of mind?
>>>
>>> Cinnebar? Mondello? Jim Bounds... you jump right on in here please :-)
>>>
>>> I actually think I have one that originated at Clasco years back,
>>> but I'd rather get new and have a better chance that I only have
>>> to do it once.
>>>
>>> At the same time I'm going to try and find a waterpump that was
>>> built for reverse rotation, i.e. serpentine setup, though I've
>>> not had cooling problems until yesterday when the fanclutch said=
bye-bye.
>>>
>>> Are there any high milagers out there that have changed timing
>>> chain and are there some that wish they had?
>>>
>>> Any and all thoughts welcomed.
>>>
>>> TIA - Heinz
>>>
>>> P.S. Any other related stuff that I should be considering while
>>> up there digging around the front?
>>>
>>
>>
>>
>Tom & Marg Warner
>Vernon Center NY
>1976 palmbeach
>"The beautiful Mohawk Vally"
>
>
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
"The beautiful Mohawk Vally"
 
Hi Manny,
I don't know if the sprocket gets changed too.
I'm hoping that Jim will chime in too and I'm going to call Mondello on
Monday (and Jim if he hasn't surfaced on the net by then :-).

I consider this one somewhat major surgery compared to other things I've
attempted on the beastie so I want to be sure I have all the ducks lined up
in a row :-) I.e. I want to do all I can while the chest is open.

Heinz
(back at my resting place at the Port of Stockton)

>Heinz I have over 70k miles on my coach and I'm having the same thoughts
>as you are.
>I bought the Cloyes timing chain from jeg's part number 9-3113. Also have
the
>water pump from Winterfeldt. What else do I need?
>
>Manny Trovao 73 Custom/ex-Glacier
>
>