4.3lx flywheel replacement

[Jgcrock99]

Good morning,
As I am summerizing my boat for this season the shop tells me my starter is going but that it is more than likely a flywheel issue. I decided to replace the starter myself in hopes they were mistaken. They were not, my flywheel has worn down and missing teeth. I have a 95 19' Chaparral with the 4.3lx motor. They are going to have to pull the motor obviously to replace the flywheel. I am in need of a new blower so I am going to have them replace this at the same time. Is there anything else I should have them replace while they have the motor out to save labor? I had my gimble bearing replaced with a bellows package about 3 years ago but I considered having them do this also.

 

[Lou C]

Check the transom mount/exhaust Y pipe for leaks/corrosion, steering pin/arm and power steering actuator for leaks/bad seals & leaky hydraulic lines.
When installing a new starter make sure the bolts are the right length; if they are too long & bottom out before clamping the starter ti the block the starter can move under torque and wear the pinion and/or the flywheel gear.
PS a good shop can replace just the ring gear not the whole flywheel.

 

[Jgcrock99]

Thanks, do you happen to know where I can find the spec length for the bolts? I'm assuming they just reused the oem bolts when they replaced the starter in 2019. I was curious about movement also but didn't feel any before I removed the starter.

 

[Lou C]

I don’t know that there is a published spec per se but here’s what I’d do, use only the ones that come with the new starter or carefully measure the height of the starter mount area. Then thread the bolts into the block and measure the length from the block to the part of the bolt head that contacts the starter mount. This dimension must be equal to or preferable less than the height of the starter mount on the starter. You don’t want the bolts to bottom out in the block before they grip the starter. I bought the starter installation kit from ARCO when I installed mine & used their knurled bolts.

 

[Lou C]

Here's a pic of the starter and bolts, see the knurled section, that keeps it from getting loose. Notice how big the old direct drive starter was. They weighed like about 20 lbs, not easy to install holding it up under the engine with one hand and getting the bolts started with the other hand! The new style PMGR units are like 8-9 lbs. And crank over way faster and draw less amps as well.

 

[Jgcrock99]

Thank you

 

[Scott06]

Good morning,
As I am summerizing my boat for this season the shop tells me my starter is going but that it is more than likely a flywheel issue. I decided to replace the starter myself in hopes they were mistaken. They were not, my flywheel has worn down and missing teeth. I have a 95 19' Chaparral with the 4.3lx motor. They are going to have to pull the motor obviously to replace the flywheel. I am in need of a new blower so I am going to have them replace this at the same time. Is there anything else I should have them replace while they have the motor out to save labor? I had my gimble bearing replaced with a bellows package about 3 years ago but I considered having them do this also.

Bilge pump if its hard to get at. Wouldnt bother with 3 year old gimbal and bellows if they were oem parts you will have lots of years left

 

[Scott Danforth]

a new ring gear is $15
a new flywheel thru aftermarket channels is $80
a new flywheel from Mercruiser is a few hundred

Your choice, spend $80 for a GM flywheel or spend $15 on a new ring gear. Most likely in stock at napa. There are two ring gears available. 153 tooth for a flywheel for 12-3/4 diameter flywheel or 168 tooth for 14" diameter

From one of my other posts https://forums.iboats.com/threads/ring-gear-1995-mercruiser-5-0-lx.731466/#post-5557031

BTW, once you have the flywheel out of the boat

buy ring gear
put ring gear in oven on 350 degrees
while the ring gear is warming up - use a chisel, cut off the old one (or heat with a torch fast and have it fall off)
use wire brush to clean up flywheel
stick flywheel in freezer
crack a beer
wipe your brow
finish the beer
remove flywheel from freezer and set on garage floor. (dont set on the wife's new granite counters)
put on welders gloves (or grab oven mitts), retrieve ring gear from oven, drop onto flywheel

it is now heat shrunk in place

use welder, tack weld in 3 areas

crack another beer

reinstall flywheel

 

[Jgcrock99]

a new ring gear is $15
a new flywheel thru aftermarket channels is $80
a new flywheel from Mercruiser is a few hundred

Your choice, spend $80 for a GM flywheel or spend $15 on a new ring gear. Most likely in stock at napa. There are two ring gears available. 153 tooth for a flywheel for 12-3/4 diameter flywheel or 168 tooth for 14" diameter

From one of my other posts https://forums.iboats.com/threads/ring-gear-1995-mercruiser-5-0-lx.731466/#post-5557031

BTW, once you have the flywheel out of the boat

buy ring gear
put ring gear in oven on 350 degrees
while the ring gear is warming up - use a chisel, cut off the old one (or heat with a torch fast and have it fall off)
use wire brush to clean up flywheel
stick flywheel in freezer
crack a beer
wipe your brow
finish the beer
remove flywheel from freezer and set on garage floor. (dont set on the wife's new granite counters)
put on welders gloves (or grab oven mitts), retrieve ring gear from oven, drop onto flywheel

it is now heat shrunk in place

use welder, tack weld in 3 areas

crack another beer

reinstall flywheel

Thank you for the information but I don't have the ability to pull it. I'm curious though, What about balance of the flywheel with a new ring gear? Is it something that would cause vibration if not properly balanced? Also, what is the best aftermarket flywheel in your opinion?

 

[dubs283]

What about balance of the flywheel with a new ring gear? Is it something that would cause vibration if not properly balanced?

The flywheel is balanced at manufacturing, the ring gear will not affect the balance of the flywheel. You do not need a new flywheel, just a ring gear. Find a shop that knows what they are doing, you will save some money by not having to buy a whole flywheel, but will spend a bit for the motor r and r

 

[Scott Danforth]

Thank you for the information but I don't have the ability to pull it. I'm curious though, What about balance of the flywheel with a new ring gear? Is it something that would cause vibration if not properly balanced? Also, what is the best aftermarket flywheel in your opinion?

no, not an issue

the best aftermarket flywheel would be a billet steel SFI rated flywheel. or your Mehling stock GM flywheel with a replaced ring gear

 

[Jgcrock99]

no, not an issue

the best aftermarket flywheel would be a billet steel SFI rated flywheel. or your Mehling stock GM flywheel with a replaced ring gear

Thank you all for your feedback. Last question, are there any magnetic sensors or otherwise on the flywheel that might need replacing while there? My tach was acting up last season and I was gonna do a gauge replacement, wasn't sure if that was something to address now.

 

[Scott Danforth]

Thank you all for your feedback. Last question, are there any magnetic sensors or otherwise on the flywheel that might need replacing while there? My tach was acting up last season and I was gonna do a gauge replacement, wasn't sure if that was something to address now.

no

your tach is the grey wire to the coil if the tach is acting up, check the connections at the gauge. and move the selector switch around a bit to clean corrosion (putting it back where you start from)