Home » Public Forums » GMCnet » Timing chain replacement (recommended parts and advice)
| Timing chain replacement [message #369706] |
Thu, 19 May 2022 16:37  |
joewilly
Messages: 40
Registered: April 2016
Location: Victor,Ia
Karma: -1
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Hello all,
I know this has been covered before and I've searched and read everything I can find but I have never done this type of maintenance before so would really appreciate your guidance/tips for getting this done right.
I know that many prefer the Cloyes double roller set but I've also heard that it's overkill for an engine with 80k that has not been rebuilt ( my engine )
I already have everything removed up to the timing cover so you know where I'm at in the process.
1. It's a 1978 Royale with 403 with appox 80k w/ good compression no known problems.
The reason for doing this is I was replacing water pump and was advised by another GMC'er to pull fuel pump and check the timing gear.
I did and found it has the nylon gear and at least 1 gear had a chip gone from 1 tooth, I didn't rotate the engine to check for more. I figured if 1 is bad the rest aren't far behind.
2. I'm not planning to rebuild the motor anytime soon ( fingers crossed ) so I'm thinking on going with a single stock replacement gear set. ( yes /no ? )
( it should last until it needs a rebuild )
What gear set would be recommended? Summit has a single chain Cloyes C-3006k set , $25.
3. What gasket set is recommended?
Felpro ? other ?
4.should I replace the harmonic damper/balancer ? anything else that needs to be replaced?
5. What's the best way to support engine when removing front mount? Do I have to lift it to get mount removed or just support it from underneath?
6.Any tips/techniques/advice would be very much appreciated. I have read the manuals and searched forums but still a little intimidated. Anything I'm missing?
Thanks in advance, your expert advise is greatly appreciated.
Joe
Joe Williams
1978 Royale rear twin
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| Re: Timing chain replacement [message #369707 is a reply to message #369706] |
Thu, 19 May 2022 17:18  |
Carl S.
Messages: 4186
Registered: January 2009
Location: Tucson, AZ.
Karma: 13
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In my opinion, you are on the right track with the stock type timing set. It will most likely outlast your engine at this point, so no use in spending the extra $$$ on a double roller set.
Fel-Pro gaskets are fine and the standard choice.
It is probably best to support the engine from the top, but you can fabricate a cradle to support it from the bottom if you prefer. Just don't try to support it by jacking against the oil pan.
As long as the harmonic balancer has not been abused (hammered on or pulled with the wrong type of puller) it should be fine, but inspect it or have an engine builder look at it. Replace if necessary or if condition is suspect.
Make sure everything is nice and clean for re-assembly and use some good RTV or "The Right Stuff" on the pan where the old and new gaskets meet.
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles, Solar battery charging. GMCSJ and GMCMI member
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| Re: Timing chain replacement [message #369713 is a reply to message #369706] |
Thu, 19 May 2022 20:30 |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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Joe,
Carl has a good set of right answers. I have almost never worked on my engine except on a stand in the middle of a big room.
I have, however, done hours of work on boat engines in place and for this reason I recommend that that you plan to take the radiator out. I have done some work on the FEAD of my engine and it is most like building a ship in a bottle. (Yes, I have seen it done and that is why I do not recommend it. - Either One.) You will have to break the A/C open and drain the coolers too. If you take it apart, you can put it all back together in layers.
Remember to bar the engine to #1 fire early on. If you do not, you will regret not doing so.
Get/borrow a real damper puller/installer. You will have to completely undress the FEAD, so take a camera in there with you and try to take too many pictures of the detail of how it all goes together. Digital is so cheap... And the film is reusable. Get the wheel well liners out and take pictures from there too.
While you are in there, it is a great time to inspect and replace hoses and other things.
The worst part is that you will have to trim that section of the pan - cover gasket to get things back together, but others have been successful with just a dab of RTV at those corners.
To support the engine, see if you know someone with a carburetor lift bracket. This is a piece that bolts on the carburetor flange. As you will be disassembling the FEAD, there will be little that is good purchase there. As said, I didn't have to do that.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: Timing chain replacement [message #369716 is a reply to message #369713] |
Thu, 19 May 2022 22:33 |
Melbo
Messages: 144
Registered: August 2018
Location: Albuquerque NM
Karma: 0
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I remember when I did it I removed the radiator and took it in to have it cleaned and checked. Removed the wheel well inserts. I got new radiator hoses and a new fan shroud. I replaced all the belts and the water pump as long as I was in there. I jacked up the front end a little at a time on each side I had removed the wheels for better access and used 18 inch sections of 4 by 6 and 2 by 6 to block it up. I don't have a shop so I was working on a gravel surface and once I had it all set up high enough to get in and out and ready to take apart I put a large piece of cardboard on the gravel so it was more pleasant to crawl in and out. You can rescue the carboard from the recycle bins. Just an FYI. I remember that I designed something to lift the engine using all thread rod that did not work. I had about 4 old screw type jacks that I used and I would be at a loss to tell you exactly where I placed them but I used two of them one on each side of the engine and blocked it up a little at a time until I was comfortable that I had the room I needed and things were stable so I could work. I remember that I had the hatch off for light. Per the previous instructions I got it to TDC with a breaker bar. Once I got it there everything seemed easy. I had not done that for many a year. Back in 1971 I worked in a pontiac service department for only six months but we replaced those nylon coated timing sprockets so I had a little bit of a memory to work with. That engine is heavy and needs to be blocked up every step of the way by my judgement. Good luck and check with the people here for the best information. They helped me get it done.
The Melbo
Albuquerque NM Bus Conversion 1978 MCI 1973 GMC
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| Re: Timing chain replacement [message #369718 is a reply to message #369706] |
Fri, 20 May 2022 08:26 |
joewilly
Messages: 40
Registered: April 2016
Location: Victor,Ia
Karma: -1
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Thanks all for your advise,
Carl, you say support engine, do I need to lift it a little to take weight off of the mount?
did you have to loosen oil pan bolts to get the gasket in or did you trim it to fit and add rtv?
Melbo, You just described my exact environment I'm working in but I added some old carpet on the cardboard to cushion these weary bones.
I'm really hoping I don't have to remove the radiator.
I have the coach up on ramps and think I have enough room to work about 12" between cover and radiator, I already removed everything from front.
Bill, what Cloyes gear set are you referring to ? Advance Auto has a C- 3006k states exact fit for 78 olds toro at $28.49 seams awfully cheap!
Matt, not sure what FEAD is but I already have everything except the damper and front mount removed and will replace all with new.
Can I set engine to #1 after I remove cover or should it be done now?
My thinking is I can remove cover and line up marks on original gear set using socket on the crank bolt, and this would put me at #1 TDC.
Am I correct on this? Is there an easier way?
Thanks all I'm planning on ordering parts today so if anyone has part #s they have used please share.
Joe
Joe Williams
1978 Royale rear twin
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| Re: Timing chain replacement [message #369725 is a reply to message #369706] |
Fri, 20 May 2022 12:05 |
lqqkatjon
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
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Senior Member |
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Joe, here is my advice on the timing chain project:
2- from what I remember, buying a non- double roller chain can be hard to find. everyone I have ever heard just buys the coyes chain. I doubt you will save anything buying a different chain.
3. felpro- there are few "sets", buy the one with everything. you want the one with the oil seal.
4. I would replace the harmonic balancer. here is why- you can have a groove in old one where it was riding on the seal, and it might leak. see #3, you can get a gasket kit with a "sleeve" for the balancer, but my experience is that sleeve is impossible to install. it is too thin and weak and bends when you try your hardest to not mess up getting it on the end of the balancer in one piece... others may have better luck then I, but I see no way of getting that sleeve installed on the old balancer.
5- Best way to support engine is from top. too much crap in way from bottom. do not lift by pan. I have a device to lift from bottom that goes around everything and lifts by oil pan bolts, but it is best to lift from topside. then your jack and stuff is not in the way when you are messing around on bottom side.
lastly #6:
take a simple aluminum ruler, or other flat piece of metal. cut out a 1/2 circle in it where the crank would be, and use that as a straight edge to line up the timing marks. I don't see the point of removing a radiator unless you are replacing the radiator because the A/C condenser still in the way. the ruler will make 100% you have your marks lined up, because when you stick your head in there sometimes looking at different angles you second guess yourself.
I would not loosen oil pan bolts. you will end up with leaks later further down the pan. pan is usually sealed to the block, and don't want to mess with that.
I razor blade off the very ends of the rubber gasket of just tips of that rubber gasket that is supposed to sandwich between the oil pan, block. and use enough RTV in those corners. I like the "maximum oil resistance permatex"
then make studs for the main bolts.. and file a little bit of the edge of the guide pins. I install the timing cover (use rtv on the gasket) by using nuts on those studs to press the cover and that lower rubber gasket into place. once that is done, call it a day, have it dry over night. Then day 2, take the nuts/studs out and install the waterpump and ect...
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
[Updated on: Fri, 20 May 2022 12:06] Report message to a moderator |
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| Re: Timing chain replacement [message #369726 is a reply to message #369725] |
Fri, 20 May 2022 12:23 |
lqqkatjon
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
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I could add- I do put up on jack stands, and remove wheel and wheel well liners. it is so much easier to deal with the $%^*ing power steering bracketry when you have that side access.
make sure when done, you should probably dump the oil, and pour in a gallon to flush out the front of what antifreeze gets in to the front of the pan. shove some rags and even some tape in the pan front careful not to allow anything to fall down into the front of the pan. it is kinda open once the timing cover is removed for screws bolts and dirt, ect to drop into the pan.
lastly - fill up the oil in the oil filler tube, and antifreeze direct into radiator. had a gmc owner pay a service shop a few years ago for this job and they fill up engine with antifreeze because they poured into the oil filler tube after they had the thing apart. he thought he messed up on the timing cover to waterpump seal, and tore it down a second time, and a second time he filled up the oil pan and the owner had that shop call me and we talked through the job and figured out the mistake.
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
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| Re: Timing chain replacement [message #369728 is a reply to message #369726] |
Fri, 20 May 2022 18:50 |
joewilly
Messages: 40
Registered: April 2016
Location: Victor,Ia
Karma: -1
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thanks Jon,
I already have wheel liners removed and up on stands, I just got the damper off - it looks pretty good and I can just barely feel a slight ridge with my fingernail.
where is the best place to hook a chain to lift motor, don't seem to be any obvious place on front to bolt to.
what do you mean by "main bolts " and do you use rtv on both sides of gasket?
thanks for your advise.
Joe Williams
1978 Royale rear twin
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| Re: Timing chain replacement [message #369729 is a reply to message #369728] |
Fri, 20 May 2022 20:07 |
lqqkatjon
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
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Senior Member |
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There are 4 thicker 3/8?? Maybe. Bolts that hold the waterpump on. Middle ones that go into block. Maybe others??
Just idea is the lower rubber gasket is really tough to just “set” the timing cover in. So I use long studs(cut head off bolt) and use nuts and washers to turn the nuts down slowly to mechanically press the cover on and massage the rubber gasket to pop into placement. I leave them tight overnight. I might have even had to put a little oil on that rubber. It is a tight fit, but once in place it seals well.
I do use rtv on both sides. I dont want leaks.
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
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| Re: Timing chain replacement [message #369730 is a reply to message #369728] |
Fri, 20 May 2022 20:13 |
lqqkatjon
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
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Senior Member |
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There us usually a loop on the driver right of the intake. Or a bolt and chain on the front of the head. You dont have to lift it much, but the front engine mount bolts to front of engine and also sits under the engine and you have to get that out from Under the engine.
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
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| Re: Timing chain replacement [message #369731 is a reply to message #369718] |
Fri, 20 May 2022 20:20 |
Carl S.
Messages: 4186
Registered: January 2009
Location: Tucson, AZ.
Karma: 13
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Senior Member |
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Yes, lift the engine a little to take the weight off the mount. Do not loosen the pan bolts, just trim the pan gasket ends, clean the mating surfaces thoroughly, and use a dab pf gasket dealer wherever there is a junction between gaskets and seals.
Also, consider investing in a two piece fan shroud. It will make your life easier now and in the future.
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles, Solar battery charging. GMCSJ and GMCMI member
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| Re: Timing chain replacement [message #369733 is a reply to message #369731] |
Sat, 21 May 2022 07:51 |
joewilly
Messages: 40
Registered: April 2016
Location: Victor,Ia
Karma: -1
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Member |
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parts are on the way from Summit arriving Tue.
will get a support built to lift engine a little
thanks again!
your help is greatly appreciated.
Joe Williams
1978 Royale rear twin
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