most ring gears ON MANUAL CLUTCH FLYWHEELS are NOT welded in place but a few are spot welded so if yours is you'll obviously need to clean up the weld points with a die grinder before installing the replacement, you can usually knock off the old ring gear by using a drift punch and working around the perimeter in a spiral until it pops free or cutting it with a hard whack from a 4 lb hammer on a very sharp cold chisel indexed between two gear teeth
heating the new gear expands it so it drops on,you usually use a propane torch and keep it constantly in motion around the ring gear perimeter because you want to heat in more or less evenly to about 300F but you don,t want to destroy the metal temper in the ring gear teeth as that induces more wear as the teeth on the ring gear become softer if annealed, once its hot its dropped in place, and it rapidly shrinks as it cools and locks in place very rapidly so push it in place fast, as its a real p.i.t.a. to remove with ZERO damage obviously having a decent Infrared TEMP GUN HELPS
http://www.fixya.com/cars/t2287493-fly_ ... eplacement
"Be very careful when removing the ring gear. You can usually just knock it off from the back bit by bit working your way around the ring. Be careful not to damage the cast iron flywheel which is not good at taking shock loads. Safest way is to drill a whole through the body of the ring gear, i.e. the area between the tooth gap and the inside diameter of the ring. This area is not hardened like the teeth. Then use a cold chisel to split the ring gear at the point where you've drilled the hole.
Best if it's possible chilling the flywheel and heating the ring gear. Best way is in an oven to get an even heat through the ring. You need to make sure you don't get it above about 250 degrees centigrade as this temperature will start to reduce the hardness of the ring gear teeth thereby significantly shortening their life. The worst way to heat the ring is likely to be with a torch because of the difficulty of getting an even heat and avoiding softening some of the ring gear teeth. You'll still get the ring on the flywheel O.K. with a torch but the effect of softening the teeth in one particular area will not be noticed from some months.
Some ring gears should only be fitted on one way. These have a chamfer on the end of each tooth to help the pinion slide into engagement. Make sure you fit them the correct way. Other rings have a larger chamfer on one side of the inside diameter. The large chamfer helps the ring slide onto the flywheel and sits better on the machined shoulder of the flywheel.
Most ring gears though can be fitted on either way.
When the ring is warmed place it on the flywheel, it should drop on fairly easily but may need tapping down during cooling. Make sure it is firmly against the shoulder. Use a feeler gauge of about 0.015" to check the gap between the ring and the shoulder, if you can get the feeler between the two in one area then tap the ring down with a copper headed hammer or an ordinary hammer with a soft metal block ... don't tap on the teeth..."
links worth watching and looking thru
http://garage.grumpysperformance.com/index.php?threads/problem-with-starter.1646/#post-12717
http://marineengineparts.com/shopsite_s ... age91.html
http://www.autopartswarehouse.com/parts ... +ring+gear
http://freeasestudyguides.com/flywheel-inspection.html
http://www.summitracing.com/parts/HAY-46-656/
http://www.theviperr.info/hobo_dnn/hobo ... cement.htm
if your replacing a ring gear, on a flex plate or flywheel, this is the route ID take, as its sure to keep the balance correct and any decent machine shop can replace a flex plate ring gear, but be aware fly wheel ring gears are generally heated and clamp on the flywheel as they shrink as they cool, flex plate will generally require careful TIG or MIG welding to hold them in place as flex plates are far thinner and more flexible
http://www.summitracing.com/parts/atp-za500
To remove the ring gear I cut it off with a torch. You do not need to cut all the way thru, but be ready to knock it off once you weak’in the ring gear with the cut. I guess one could use a dremel tool or a cut off wheel in a hand grinder to git the same result. Either way it should not be hard to remove or cut more are more slots to relieve the tension.
Next you will see I have the flywheel and the ring gear set up for instillation. I use a oxygen/acetylene torch out fit to heat the ring gear set up on 2 jack stands. You will need to heat the ring gear to around 400 deg. You are look’in for the ring gear to turn blue/hot not red. Its hard to splain zackly when you have it just rite to install. It takes ’bout 12 seconds for me to run the torch around the ring gear and ’bout 10 times around the ring gear should be read to install. You kin grab the ring gear with a set of channel locks and check for fit. I do prefer that It will bout slip on and I need to tap it on but if it slips on or falls on it should be OK, just try not to over do it with the heat. In the old days it seemed it took awhile to heat’em up enough to slip on. Now it seems it does not take as much heat and if I heat to blue/hot I may have heated it to far. Let the ring gear cool naturally DO NOT Try and cool it, go drink a beer or 2, 30min. And it should be ready to install.
If the ring gear has a taper to the teeth install with the taper to to the rear of the flywheel clutch side, if no taper it does not matter witch way you install it. I always look at the I.D. of the ring gear and if it has a bevel I install the bevel to the flywheel side first.
I have not tried enny of this but will throw this out. It has been said that you kin throw yer ring gear in a oven pre heat to 400 deg. And bake fer 30 min. I will say that when you take it out and it does not fall on DO NOT try and beat it on, that izz if you kin git it back off the fly wheel. I would beat it off but not on so have the necessary tools handy to knock it off quickly. I see no need to freeze the flywheel. I have never tried a propane torch but spec it would werk give’in time. You will not believe how quicky the ring gear will grow when heated properly and how much it will shrink when installed and allowed to cool.
there are 153 (about 12")
and 168 tooth (about 14")
fly wheel,
but in every case the starter must be mounted, on the block with the correct matching bell housing on the block to correctly contact the flywheel SIZE your using
Default SBC Flywheel & Flexplate part numbers
Small Block Chevy Flywheel Part Numbers
Part # DIA. Teeth Comments
3991406 Flywheel, LW Nodular Iron for HD 10.5" Clutch
3991469 14" 168 two-piece seal, internally balanced
3986394 14" 168 400 External balance, two-piece seal
10105832 14" 168 86-later, one-piece rear seal, ext. balance
14088671 12.75" 153 86-later, one piece rear seal, int. balance
14085720 12.75" 153 Lightweight (15 lbs.), nodular iron, two-piece seal, int bal Will work with a clutch diameter of 10.4" only. Crank flange bolt pattern is 3.58". Will work with a clutch diameter of 10.4" OR 11.0". Crank flange bolt pattern is 3.0"
14088646 12.75" 153 86-up, Lightweight (15 lbs.), nodular iron, one-piece rear seal, ext bal
14088648 14" 168 86-up, one-piece rear seal, ext. balance
14088650 12.75" 153 86-up, one-piece rear seal, ext balance Will work with a clutch diameter of 10.4" only. Crank flange bolt pattern is 3.0"
10174482 89-up with six-speed m/t, requires starter (10455709)
Common clutch sizes are: 10.4", 11.0", and 11.85". Some flywheels are drilled for two different clutch patterns.
12.75" are usually 153 tooth and the other larger 14" diam. are 168 tooth flywheel or flex plate designs, the larger 14"/168 tooth designs fit the much stronger 11" clutches.... obviously the 14" can use a larger clutch, but require a larger bell housing that is why some stock bell housings won,t fit the larger fly wheels and of course the starter used must match
http://www.4speedconversions.com/chevy-bellhousings.html
http://www.singster.co.uk/mascot%20may% ... 02001.html
heating the new gear expands it so it drops on,you usually use a propane torch and keep it constantly in motion around the ring gear perimeter because you want to heat in more or less evenly to about 300F but you don,t want to destroy the metal temper in the ring gear teeth as that induces more wear as the teeth on the ring gear become softer if annealed, once its hot its dropped in place, and it rapidly shrinks as it cools and locks in place very rapidly so push it in place fast, as its a real p.i.t.a. to remove with ZERO damage obviously having a decent Infrared TEMP GUN HELPS
http://www.fixya.com/cars/t2287493-fly_ ... eplacement
"Be very careful when removing the ring gear. You can usually just knock it off from the back bit by bit working your way around the ring. Be careful not to damage the cast iron flywheel which is not good at taking shock loads. Safest way is to drill a whole through the body of the ring gear, i.e. the area between the tooth gap and the inside diameter of the ring. This area is not hardened like the teeth. Then use a cold chisel to split the ring gear at the point where you've drilled the hole.
Best if it's possible chilling the flywheel and heating the ring gear. Best way is in an oven to get an even heat through the ring. You need to make sure you don't get it above about 250 degrees centigrade as this temperature will start to reduce the hardness of the ring gear teeth thereby significantly shortening their life. The worst way to heat the ring is likely to be with a torch because of the difficulty of getting an even heat and avoiding softening some of the ring gear teeth. You'll still get the ring on the flywheel O.K. with a torch but the effect of softening the teeth in one particular area will not be noticed from some months.
Some ring gears should only be fitted on one way. These have a chamfer on the end of each tooth to help the pinion slide into engagement. Make sure you fit them the correct way. Other rings have a larger chamfer on one side of the inside diameter. The large chamfer helps the ring slide onto the flywheel and sits better on the machined shoulder of the flywheel.
Most ring gears though can be fitted on either way.
When the ring is warmed place it on the flywheel, it should drop on fairly easily but may need tapping down during cooling. Make sure it is firmly against the shoulder. Use a feeler gauge of about 0.015" to check the gap between the ring and the shoulder, if you can get the feeler between the two in one area then tap the ring down with a copper headed hammer or an ordinary hammer with a soft metal block ... don't tap on the teeth..."
links worth watching and looking thru
http://garage.grumpysperformance.com/index.php?threads/problem-with-starter.1646/#post-12717
http://marineengineparts.com/shopsite_s ... age91.html
http://www.autopartswarehouse.com/parts ... +ring+gear
http://freeasestudyguides.com/flywheel-inspection.html
http://www.summitracing.com/parts/HAY-46-656/
http://www.theviperr.info/hobo_dnn/hobo ... cement.htm
if your replacing a ring gear, on a flex plate or flywheel, this is the route ID take, as its sure to keep the balance correct and any decent machine shop can replace a flex plate ring gear, but be aware fly wheel ring gears are generally heated and clamp on the flywheel as they shrink as they cool, flex plate will generally require careful TIG or MIG welding to hold them in place as flex plates are far thinner and more flexible
http://www.summitracing.com/parts/atp-za500
To remove the ring gear I cut it off with a torch. You do not need to cut all the way thru, but be ready to knock it off once you weak’in the ring gear with the cut. I guess one could use a dremel tool or a cut off wheel in a hand grinder to git the same result. Either way it should not be hard to remove or cut more are more slots to relieve the tension.
Next you will see I have the flywheel and the ring gear set up for instillation. I use a oxygen/acetylene torch out fit to heat the ring gear set up on 2 jack stands. You will need to heat the ring gear to around 400 deg. You are look’in for the ring gear to turn blue/hot not red. Its hard to splain zackly when you have it just rite to install. It takes ’bout 12 seconds for me to run the torch around the ring gear and ’bout 10 times around the ring gear should be read to install. You kin grab the ring gear with a set of channel locks and check for fit. I do prefer that It will bout slip on and I need to tap it on but if it slips on or falls on it should be OK, just try not to over do it with the heat. In the old days it seemed it took awhile to heat’em up enough to slip on. Now it seems it does not take as much heat and if I heat to blue/hot I may have heated it to far. Let the ring gear cool naturally DO NOT Try and cool it, go drink a beer or 2, 30min. And it should be ready to install.
If the ring gear has a taper to the teeth install with the taper to to the rear of the flywheel clutch side, if no taper it does not matter witch way you install it. I always look at the I.D. of the ring gear and if it has a bevel I install the bevel to the flywheel side first.
I have not tried enny of this but will throw this out. It has been said that you kin throw yer ring gear in a oven pre heat to 400 deg. And bake fer 30 min. I will say that when you take it out and it does not fall on DO NOT try and beat it on, that izz if you kin git it back off the fly wheel. I would beat it off but not on so have the necessary tools handy to knock it off quickly. I see no need to freeze the flywheel. I have never tried a propane torch but spec it would werk give’in time. You will not believe how quicky the ring gear will grow when heated properly and how much it will shrink when installed and allowed to cool.
there are 153 (about 12")
and 168 tooth (about 14")
fly wheel,
but in every case the starter must be mounted, on the block with the correct matching bell housing on the block to correctly contact the flywheel SIZE your using
Default SBC Flywheel & Flexplate part numbers
Small Block Chevy Flywheel Part Numbers
Part # DIA. Teeth Comments
3991406 Flywheel, LW Nodular Iron for HD 10.5" Clutch
3991469 14" 168 two-piece seal, internally balanced
3986394 14" 168 400 External balance, two-piece seal
10105832 14" 168 86-later, one-piece rear seal, ext. balance
14088671 12.75" 153 86-later, one piece rear seal, int. balance
14085720 12.75" 153 Lightweight (15 lbs.), nodular iron, two-piece seal, int bal Will work with a clutch diameter of 10.4" only. Crank flange bolt pattern is 3.58". Will work with a clutch diameter of 10.4" OR 11.0". Crank flange bolt pattern is 3.0"
14088646 12.75" 153 86-up, Lightweight (15 lbs.), nodular iron, one-piece rear seal, ext bal
14088648 14" 168 86-up, one-piece rear seal, ext. balance
14088650 12.75" 153 86-up, one-piece rear seal, ext balance Will work with a clutch diameter of 10.4" only. Crank flange bolt pattern is 3.0"
10174482 89-up with six-speed m/t, requires starter (10455709)
Common clutch sizes are: 10.4", 11.0", and 11.85". Some flywheels are drilled for two different clutch patterns.
12.75" are usually 153 tooth and the other larger 14" diam. are 168 tooth flywheel or flex plate designs, the larger 14"/168 tooth designs fit the much stronger 11" clutches.... obviously the 14" can use a larger clutch, but require a larger bell housing that is why some stock bell housings won,t fit the larger fly wheels and of course the starter used must match
http://www.4speedconversions.com/chevy-bellhousings.html
http://www.singster.co.uk/mascot%20may% ... 02001.html
Last edited by a moderator: