76 Edgemonte Build

odintech

odintech

Member
May 12, 2023
39
18
18
41
Springville Ut
odin.tech
Greetings GMCers. I am closing on a purchase of a 76 Edgemonte next week. I will be replacing one of the airbags and have one on its way from Cinnabar Eng. I will also be cleaning and repacking/replacing the rear bearings before bringing it to Utah from Seattle. Lots of upgrades are planned but I would appreciate advice on how to prioritize them.

Planned:
EFI upgrade FiTech
Springfield Ignition Recurve/rebuild of HEI
Final drive 3.55
LED Lights all around
MicroLevel
More Gauges, Trans Temp, Vacuum, Tach
Rebuilt Knuckes for the front end.
Paint
Replace Shag with LVT

Anything I'm missing?
 
Odin,
After you have looked at the page linked above, sit down and remember that it has to be safe and reliable first.
Ergo, I would reorder your list:
Repacking the rear and inspecting the brakes is good. Be aware that some of the rear seals sold be number are wrong and the rubber will not clear the bearing.
Rebuilt Knuckes for the front end. I hope you can get a pair from Dave Lenzi.
Springfield Ignition Recurve/rebuild of HEI, and a spare set of the module, coil and pickup with needed tools.
LED Lights all around, clearance lights are first. Then tail and stop. Inside is good and saves house bank.
MicroLevel I love mine.
More Gauges, Trans Temp, Vacuum, Tach - think about a Digipanel
Final drive 3.55
EFI upgrade FiTech, but don't stop until you have the EBL set.
Paint
Replace Shag with LVT

Please use and enjoy her as soon as you can. That makes the work more rewarding.
Please ask here before you spend any serious money.

And Please, go up to the little O circle at the top right and fill in a sigfile with a real name because we like to know who we are helping, a short about the coach including major mods that might matter and finally a geographic reference. By becoming and owner and being here you have just collected a couple hundred brand new old friends. There may be someone in striking distance that can at least look at your problem and advise.
Also, do not depart without a printed copy of the the GMC Assist list in your hand and a charged cell phone. If you are lucky, you won't have dire need of either but both will be as comforting as a lifejacket in bad weather.

Remember to come back here and tell us all how it went.

Matt_C
 
Matt Colie said:
Odin,
After you have looked at the page linked above, sit down and remember that it has to be safe and reliable first.
Ergo, I would reorder your list:
Repacking the rear and inspecting the brakes is good. Be aware that some of the rear seals sold be number are wrong and the rubber will not clear the bearing.
Rebuilt Knuckes for the front end. I hope you can get a pair from Dave Lenzi.
Springfield Ignition Recurve/rebuild of HEI, and a spare set of the module, coil and pickup with needed tools.
LED Lights all around, clearance lights are first. Then tail and stop. Inside is good and saves house bank.
MicroLevel I love mine.
More Gauges, Trans Temp, Vacuum, Tach - think about a Digipanel
Final drive 3.55
EFI upgrade FiTech, but don't stop until you have the EBL set.
Paint
Replace Shag with LVT

Please use and enjoy her as soon as you can. That makes the work more rewarding.
Please ask here before you spend any serious money.

And Please, go up to the little O circle at the top right and fill in a sigfile with a real name because we like to know who we are helping, a short about the coach including major mods that might matter and finally a geographic reference. By becoming and owner and being here you have just collected a couple hundred brand new old friends. There may be someone in striking distance that can at least look at your problem and advise.
Also, do not depart without a printed copy of the the GMC Assist list in your hand and a charged cell phone. If you are lucky, you won't have dire need of either but both will be as comforting as a lifejacket in bad weather.

Remember to come back here and tell us all how it went.

Matt_C
Click to expand...
Thanks, Matt!

I ordered the timken bearings and seal by number. Hopefully they work as intended. Can the seals be clearanced to fit?
 
Jason,
I was told that they can. The easy way to test them is to roll a 1/4 something (I use a short piece of CU tube under the seal. The lip should not bend. I know that some have used set back plates (a plate cut to the seal diameter and relieved enough to have the seal clear) to install the seals at the correct depth.
Matt_C
 
Matt Colie said:
Odin,
After you have looked at the page linked above, sit down and remember that it has to be safe and reliable first.
Ergo, I would reorder your list:
Repacking the rear and inspecting the brakes is good. Be aware that some of the rear seals sold be number are wrong and the rubber will not clear the bearing.
Rebuilt Knuckes for the front end. I hope you can get a pair from Dave Lenzi.
Springfield Ignition Recurve/rebuild of HEI, and a spare set of the module, coil and pickup with needed tools.
LED Lights all around, clearance lights are first. Then tail and stop. Inside is good and saves house bank.
MicroLevel I love mine.
More Gauges, Trans Temp, Vacuum, Tach - think about a Digipanel
Final drive 3.55
EFI upgrade FiTech, but don't stop until you have the EBL set.
Paint
Replace Shag with LVT

Please use and enjoy her as soon as you can. That makes the work more rewarding.
Please ask here before you spend any serious money.

And Please, go up to the little O circle at the top right and fill in a sigfile with a real name because we like to know who we are helping, a short about the coach including major mods that might matter and finally a geographic reference. By becoming and owner and being here you have just collected a couple hundred brand new old friends. There may be someone in striking distance that can at least look at your problem and advise.
Also, do not depart without a printed copy of the the GMC Assist list in your hand and a charged cell phone. If you are lucky, you won't have dire need of either but both will be as comforting as a lifejacket in bad weather.

Remember to come back here and tell us all how it went.

Matt_C
Click to expand...
One more question. You would recommend the EBL gm based system over the fitech?
 
Jason,
I do not know much about the Fitech system, but the GM/EBL system is all GM stock parts and the calibration can be trimmed by the user very easily. That is a selling point to me after doing calibration for EO customers for so many years.
Matt_C
 
Well, an update on the machine. Engine was running well and then I started climbing the grade to come out of Seattle heading back towards Utah when the engine overheated and shut down. I had it towed to a local diesel and RV shop in North Bend Washington I am hoping that I didn’t seize the engine or spin bearings. I will check in with the RV place on Monday to see if they have experience with these engines and to see if they can do a basic diagnosis for me. I am flying back out to Utah first thing tomorrow morning. So disappointed. I should have been paying attention to the gauges and pulled over and let it cool off.
 
Matt Colie said:
Jason, o
There are lots of things that could have shut the engine down in the conditions sited. You should have hope that it was one of the simple and non-fatal ones.
Matt_C
Click to expand...
Yeah, the engine gauges were water temperature on the Highmark oil pressure on the low mark when we came to a stop at the bottom of the on-ramp. It ran for about 30 seconds shut off and the coolant bottle top popped and fountained about 3 gallons of coolant on the road.
 
Jason,
If you have the stock coolant temperature sender, then that could be bad. If not, you had what engine people describe as a "Wet Overheat". Wet overheats are seldom fatal, but they can take out a head gasket.
It the shop does not pronounce it, you should have your mechanic (someone you trust greatly) do a repull on the head bolts. This just means pull on the bolts at the specified load and see if ANY move at all. One or two may creep a little, but if more than that, then do the back-off and retorque all around. This is a Major League PITA as it will require undressing the top of the engine.....
Matt_C (the refugee from dynoland)
 
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Matt Colie said:
Jason,
If you have the stock coolant temperature sender, then that could be bad. If not, you had what engine people describe as a "Wet Overheat". Wet overheats are seldom fatal, but they can take out a head gasket.
It the shop does not pronounce it, you should have your mechanic (someone you trust greatly) do a repull on the head bolts. This just means pull on the bolts at the specified load and see if ANY move at all. One or two may creep a little, but if more than that, then do the back-off and retorque all around. This is a Major League PITA as it will require undressing the top of the engine.....
Matt_C (the refugee from dynoland)
Click to expand...
So going down the road and that coach on flatland the temperature gauge is reading between the quarter and a half mark on the high side. The oil pressure when cold was reading at about 3/4 and then drop to about 3/8 on flatland.
 
Matt Colie said:
Jason,
If you have the stock coolant temperature sender, then that could be bad. If not, you had what engine people describe as a "Wet Overheat". Wet overheats are seldom fatal, but they can take out a head gasket.
It the shop does not pronounce it, you should have your mechanic (someone you trust greatly) do a repull on the head bolts. This just means pull on the bolts at the specified load and see if ANY move at all. One or two may creep a little, but if more than that, then do the back-off and retorque all around. This is a Major League PITA as it will require undressing the top of the engine.....
Matt_C (the refugee from dynoland)
Click to expand...
Currently getting quotes to trailer it to Utah where I can work on it with my mechanic
 
Matt Colie said:
Jason,
If you have the stock coolant temperature sender, then that could be bad. If not, you had what engine people describe as a "Wet Overheat". Wet overheats are seldom fatal, but they can take out a head gasket.
It the shop does not pronounce it, you should have your mechanic (someone you trust greatly) do a repull on the head bolts. This just means pull on the bolts at the specified load and see if ANY move at all. One or two may creep a little, but if more than that, then do the back-off and retorque all around. This is a Major League PITA as it will require undressing the top of the engine.....
Matt_C (the refugee from dynoland)
Click to expand...
Repull as in torque wrench on head bolts and check for movement?
 
Crazy thought. Has anyone flat towed these with a heavy rated towbar and surge braking? I’m thinking I would have to use the splined section of the cv axle to hold the hub in the knuckle but it might work.
 
Jason,
First, yes, that is what re-pull means. Sorry I did not include the translation the first time.
Second, flat towing has been proposed before, but I do not believe anybody has ever done it a significant distance.
You did not say how far you have to go. I wish you luck in any case.
We recently had to recover from a wet overheat when the A/C belt when off and cleared all the other belts off the engine. I lucked out.
Matt_C
 
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A friend of mine towed a GMCMH (6 down) about 100mi with his 1ton Chevy diesel PU. Used a towbar that he rigged to the front bumper brackets with safety chains and a Brake Buddy for brakes. He also removed both front axles so that the transmission and final drive were not engaged in any way and took all state and county roads, NO interstate travel. Ran a set of wires to the rear of the coach for turn signals and stop. Took the ends off of the axles and stuck them in the front hubs ( to keep the bearings clean). Drove at or under 50mph. Successful drive with no issues. Think this out throughly before you attempt this.
 
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Matt Colie said:
Jason,
First, yes, that is what re-pull means. Sorry I did not include the translation the first time.
Second, flat towing has been proposed before, but I do not believe anybody has ever done it a significant distance.
You did not say how far you have to go. I wish you luck in any case.
We recently had to recover from a wet overheat when the A/C belt when off and cleared all the other belts off the engine. I lucked out.
Matt_C
Click to expand...
900 miles or so
 
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We overheated sitting in traffic in SC, fan clutch was shot. It was a wet overheat though, just blew steam and coolant on ground. Waited for it to cool down, traffic to clear, topped off radiator with water from the kitchen sink and continued on to our destination. Changed fan clutch when we arrived.

No damage to engine that I can tell. Hopefully yours is the same.
 
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