Best method to install crank gear
Thread Starter
Instructor
Joined: Apr 2008
Posts: 109
Likes: 2
From: Hillsville VA
Best method to install crank gear
I'm installing a new timming chain and need a good method to install crank gear. I really dont want to beat it on with a hammer if I can get away with it. I though about heating it with a propane torch but wasnt sure if that would damage it in any way, or if it would even help.
Thanks, Kevin
Thanks, Kevin
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Three ways come to mind.
Do you have an oven close by? Simply heat the gear to 250 or so, grab it with some locking pliers or a thick oven mitt, and QUICK before it cools, slid it on to the crank and it should seat perfectly and cool in place.
If you can find one, a short length of heavy pipe that'll fit over the snout of the crank would be fine. Use the pipe and a mini sledge to hammer it on until it seats against the shoulder.
If you're timid and don't want to run through the house with a very hot gear in your hands, and you don't have a large diameter pipe and a mini sledge, you can slide in on the snout, and slowly tap it on with a hammer and rod. I usually do it like a clock, striking it at 12, then 1, 2 ,3, and so on all the way around over and over again until it's seated. Every time you punch it, not super heavy, but a firm tap, it'll slide just a bit further on.
Do you have an oven close by? Simply heat the gear to 250 or so, grab it with some locking pliers or a thick oven mitt, and QUICK before it cools, slid it on to the crank and it should seat perfectly and cool in place.
If you can find one, a short length of heavy pipe that'll fit over the snout of the crank would be fine. Use the pipe and a mini sledge to hammer it on until it seats against the shoulder.
If you're timid and don't want to run through the house with a very hot gear in your hands, and you don't have a large diameter pipe and a mini sledge, you can slide in on the snout, and slowly tap it on with a hammer and rod. I usually do it like a clock, striking it at 12, then 1, 2 ,3, and so on all the way around over and over again until it's seated. Every time you punch it, not super heavy, but a firm tap, it'll slide just a bit further on.
Race Director
Joined: Apr 2000
Posts: 17,654
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
I used a CompCams crank gear installer. Used with my harmonic balancer installer it really makes it easy. Oh yes I have allot of tools 
http://www.jegs.com/i/Comp%20Cams/249/4789/10002/-1
http://www.jegs.com/i/Comp%20Cams/249/4789/10002/-1
Burning Brakes
Joined: Dec 2007
Posts: 952
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I used a CompCams crank gear installer. Used with my harmonic balancer installer it really makes it easy. Oh yes I have allot of tools
http://www.jegs.com/i/Comp%20Cams/249/4789/10002/-1
http://www.jegs.com/i/Comp%20Cams/249/4789/10002/-1
Heating in an oven, or using a propane torch is also fine.
NEVER use a hammer. The babbit thrust bearing is EASILY damaged this way.
Burning Brakes
Joined: May 2004
Posts: 1,100
Likes: 3
From: belle plaine ks
If you can find one, a short length of heavy pipe that'll fit over the snout of the crank would be fine. Use the pipe and a mini sledge to hammer it on until it seats against the shoulder.
Only if you want to break the thrust flange off the rear main. Not a good idea.
Go to autozone and rent the installation tool or buy one.
Only if you want to break the thrust flange off the rear main. Not a good idea.
Go to autozone and rent the installation tool or buy one.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Have you ever seen a case where this happened? I'm just curious. I know in theory, if you whale on it you'll harm something, but the gear is not that hard to get on...not like a balancer, and a few quick taps and it's on good and solid. Almost everyone I know uses this method...I use the oven method because it's close...but I don't know of one single case where the main bearings were damaged when a hammer was carefully used.
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Burning Brakes
Joined: Dec 2007
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Have you ever seen a case where this happened? I'm just curious. I know in theory, if you whale on it you'll harm something, but the gear is not that hard to get on...not like a balancer, and a few quick taps and it's on good and solid. Almost everyone I know uses this method...I use the oven method because it's close...but I don't know of one single case where the main bearings were damaged when a hammer was carefully used.
It's the same to me as suggesting someone install a bad fitting windshield with a jack hammer.
Even if it did not crack, babbit is soft, and you could probably measure the compression with a feeler gauge.
The OP asked the BEST way to install it. Pounding on an installed crank is the WORST way.
Melting Slicks
Joined: Dec 2000
Posts: 3,407
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From: Carmichael CA
Uhm...the "best" way to install the crank gear is to take it nice and easy...line it up properly and press it onto the crankshaft. Some genius drilled and tapped the crankshaft so a bolt can fit into it...it's simply amazing...you find a bolt that is long enough to get started with the gear lined up and start torquing down on it...keep the crankshaft from spinning with whatever means you have (make sure you don't damage it!). It doesn't take much more than like 45ftlbs to get it started...it gets easier when the gear is partly on.
Burning Brakes
Joined: May 2004
Posts: 1,100
Likes: 3
From: belle plaine ks
I have seen them cracked because of that. What do you suppose that does for somebody using a clutch set up in their car? They will finish off the thrust main first time they lay some rubber. Also if you crack or bend the the thrust main you changed the tolerance on the crankshaft travel. Which has a really big effect on everything attached to that crankshaft. Why do you suppose they make the tool? Reason it out, it is not a good idea. You won't find that going on at a major engine builders facility. There is a tolerance for main bearing end thrust. Look it up and get back to me and tell me what it is.
Burning Brakes
Joined: May 2004
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From: belle plaine ks
Pro
Joined: Jul 2005
Posts: 517
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From: Peoria IL
I haven't seen thrust bearings damaged this way nearly as often as I've seen crankshafts bent or broken this way.
I use the Moroso tool. It's basically the same thing as the Comp Cams tool. It's the right way to do the job, and in the long run it's the easiest.
I use the Moroso tool. It's basically the same thing as the Comp Cams tool. It's the right way to do the job, and in the long run it's the easiest.
Drifting
Joined: Feb 2005
Posts: 1,738
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From: San diego ca
before I owned the proper tool I used a short length of Wooden dowel and a light hammer...the wooden dowel is softer than the bearing.
there is no need for a Sledgehammer, which implies (but wasnt DB's intention im sure) wailing away on it like we are making a horseshoe, the gear will walk on just fine with light rapping. that kind of rapping isnt going to do any kind of damage to the thrust surface of the bearing.
all that said, get the tool and do it right... its not like its all that expensive.
there is no need for a Sledgehammer, which implies (but wasnt DB's intention im sure) wailing away on it like we are making a horseshoe, the gear will walk on just fine with light rapping. that kind of rapping isnt going to do any kind of damage to the thrust surface of the bearing.
all that said, get the tool and do it right... its not like its all that expensive.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
there is no need for a Sledgehammer, which implies (but wasnt DB's intention im sure) wailing away on it like we are making a horseshoe, the gear will walk on just fine with light rapping. that kind of rapping isnt going to do any kind of damage to the thrust surface of the bearing.
You're correct that's not what I meant. I feel I have greater control using a mini sledge. Much slower and smaller taps and it's more even and concentrated. I usually used a long brass drift if I couldn't find the pipe, and it taps on very easily.
Lets be clear, there are lots of uses for a hammer on a Vette, and swinging it hard enough will damage ANYTHING. However, using it correctly with the right touch will accomplish a lot of things without damaging anything.
Thread Starter
Instructor
Joined: Apr 2008
Posts: 109
Likes: 2
From: Hillsville VA
Sorry about all the problems this question caused. I thought this thread was done. I have had the gear on for a couple days.
Durango_Boy, I took your advice and heated it. I may not have got it hot enough so I got it most of the way on. I beat it on with a BFH the rest of the way. May have slightly chipped a tooth but I think it is ok. Still better than the factory one.
Just kidding, I did "tap" it the rest of the way with a hammer and a piece of pine.
Thanks for all the info, Kevin
Durango_Boy, I took your advice and heated it. I may not have got it hot enough so I got it most of the way on. I beat it on with a BFH the rest of the way. May have slightly chipped a tooth but I think it is ok. Still better than the factory one.
Just kidding, I did "tap" it the rest of the way with a hammer and a piece of pine.Thanks for all the info, Kevin
Le Mans Master
Joined: Aug 2003
Posts: 7,720
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From: Chattanooga TN
Cool the crank if you can to shrink it; wrap the snout in cold towels or stick the crank in the freezer if it is out. Heat the gear in the oven or in a pan of hot water on a hot plate right next to the car. Put it on using welding gloves. If you are fast enough it will go all the way.