Help! Flywheel Ring Gear pull through bottom or top?

[Satdun027]

1981 4x4 king cab california model

My 720 has sat for a couple months now - i've got a double whammy going on. 
There is a carb issue (should be easily fixable) and a starter/fly wheel...ring gear...issue? So I can't even begin to really start tackling the carb issue because i have to pop start it just to see whats going on and its all a @#$ing nightmare really. I have spent nights upon nights pop starting it only to have it run for a sec with a high rpm...or a fuel issue - you can't imagine the frustration! (actually im sure you can)

I've only found a little information on replacing the ring gear but it seems to be popular opinion that pulling the engine and transmission out together is easier than lowering the trans out the bottom? Can i get some solid advice please? its a large task for me since i dont exactly have a garage and live in the middle of nowhere - hyampom ca , look it up... 

Anyways i need guidance as to what to do - my plan right now is to pull the engine - replace ring gear - buy weber 

i feel like thats the right thing...thanks in advance.

[datzenmike]

What exactly is the truck doing that you think the ring gear is the problem?

 

If the starter clicks but does not turn or if it spins freely but does not turn the engine it may not be the flywheel, in fact probably not.

 

What is pop starting?

[Crashtd420]

I agree with mike ... take a look at the starter first.... you can easily have that tested.... or test yourself on a bench... just make sure you hang onto it....

 

And mike really ... you never had to pop start one of your datsuns....

With ignition on, Get it rolling, put in gear and pop the clutch.... turns the motor over and starts it...

[Crashtd420]

Plus with the starter out you'll be able to see the ring gear....

If it is your problem you should see all the teeth rounded over or broken....

Alot easier to do that and determine if its your problem or not with out pulling the engine and trans....

[wayno]

Your issue is likely the starter and not the ring gear, if you turn the key to the start position and the starter motor spins but doesn't engage that is likely a starter solenoid issue.

As mentioned, remove the starter and look at the teeth of the ring gear, if it is missing teeth or completely gone then it is time to pull the engine, if it is missing you would likely have bigger issues as there really isn't enough room in the bellhousing for a loose ring gear of pieces at the bottom, it would sound like the transmission had blown up and you would likely have holes in the transmission case from the rotating flywheel/clutch cover assembly making room for the pieces of ring gear.

Tell us exactly what the starter is doing!!!

[Stoffregen Motorsports]

If it started fine before it sat, it's not going to be the ring gear. They don't go bad over time.

 

Try a jump start. If that works, then it's not your ring gear. Could be the starter went bad from not being used, but not he ring gear.

[G-Duax]

Could be the bendix on the starter.

When you pull the starter to test it, make sure the little gear on the starter jumps out to as to engage the ring gear.

If it doesn't, then the bendix is sticking.

Sometimes they can be lubed, and they will work fine.

 

When you look at the ring gear, minor damage, and flakes of metal are the result of the bendix not properly engaging the ring gear.

With a new starter, a slightly damaged ring gear will still work fine for many years.

[wayno]

I have at least 3 starters that are a major pain when they are in my truck, but they test on the garage floor just fine in every aspect, mostly they just spin free when I hit the key in the truck, but the one gear reduction type engages but the moment the engine kicks it disengages and spins free, the motors on them are all fine, it's that damned starter solenoid that is bad, the stuff they sell now is crap, I find getting one out of a vehicle in the wrecking yard is the best, the older the starter the better, OEM is awesome.

[Cheetahking]

I had a ring gear issue once.  The starter would sort of engage at one point on the ring gear - and spin - this would rotate the engine far enough to have it engage a non worn part of the ring gear and work fine.  

 

The problem with the ring gear is that the engine tends to stop at the same point every time, so the gear wears in this area.  Cheap fix is to flip the ring gear over and rotate.  Stupid in my option given the amount of work to get to it.   

 

I agree with above - you should pull the starter and take a look at the gear on the starter - and you can turn the motor and inspect the ring gear as well.  More likely it is a starter issue that it is a ring gear problem.  

[Satdun027]

Hey sorry for the delayed response
It is very much the ring gear. I already replaced the starter - after a few forced attempts at starting the truck i pulled the new starter off and looked inside at the ring gear - the teeth are significantly damaged.(brand new starter = ruined)  Good news is i already have the replacement ring
- just can't decide on how to go about doing it. 
thanks all.

[Satdun027]

ok - I'm going to reinstall the old starter after examining the bendix and get a clear idea of exactly what its doing then i'll report back. 
but seriously i think its the ring gear...the damage is pretty bad - i'll try an get photos asap
thanks again.

[datzenmike]

The old one will hammer off or slice carefully with cut of wheel. In some cases the ring is mostly worn on the front or leading edge and you can just put it on backwards, but if you have a new one.... I don't think it matters which way it comes off or goes on.

 

Put flywheel in freezer over night. When ready to install, heat starter ring gear to at least 350-400 in the oven. When ready, slip it onto the cold flywheel and tap into place. As the flywheel warms to ambient and expands the ring tightens on.

 

All manuals caution to never drop a flywheel and this is why. 

[Satdun027]

yes but as far as getting to the ring gear itself? Should i go through the bottom or the top? The only info i've seen online is that people had an easier time just pulling the engine out rather than dropping the bottom - i don't exactly have an engine hoist but i do have access to everything i need to lift it out if need be - i've just never worked on this part of the truck before so I'm looking for any and all advice thanks

[datzenmike]

Having removed the transmission before to get at the flywheel and how tight it is in there I would go with lifting the engine out.

[captain720]

Pulling a Z24 is easy

[Charlie69]

Pull engine, remove fly wheel, heat flywhell ring gear with oxy acetelene torch until red hot ring gear will fall off.  flip ring gear over re heat and drop in over flywheel while hot.  Let cool re instal fly wheel on engine, install engine replace clutch kit throughout bearing input shaft bearing install engine. fix carb problem drive and enjoy.

[datzenmike]

Red hot will anneal it and risk making it softer. Better just hammer it off.

[Satdun027]

well i have a new ring gear so i'll just use the new one once i actually acquire the proper space and tools to pull the engine. I live in the middle of nowhere currently and am having a hard time finding a good space and a proper hoist. block and tackle i suppose?

]

my second issue is an idle problem.
as i said before i have to pop start the truck in its current condition - I usually pop it in 2nd gear to make it easier 
When the engine starts it seems to be actuated and is getting so much gas that its driving on its own. If i push in the clutch the RPMs jump up to 3k and it will hold there until i shift into gear. Upon shifting into 3rd gear the rpms fall dramatically (almost all the way to zero) and the engine begins to die, if i push in the clutch at this moment the rpms will jump back up to 3k.
does this seem like a choke issue? 
when i lift the hood after this exercise there is an excessive fuel smell - i believe the rubber boot on the accelerator arm is leaking - either that or somewhere around the 'banjo' fitting that carries gas into the floatbowl. Narrowing down the issue is beyond frustrating since i have to pop start it each time just to get an idea of whats wrong. i've tried adjusting the idle screw during this chaos but its hard to say if its helping or not - to be honest its hard to focus with the engine roaring at 3k as i scramble to get to the carb - did i mention that the exhaust is cut off at the non existent CAT ... so its loud
any help is appreciated. 
 

[datzenmike]

Do you have a tach?

 

It's normal on start up to have a faster idle 1,800 to 2,200 give or take. The choke forces a rich condition and more air is needed to burn it and the RPMs go up. This is to speed up the warm up process. The choke will turn off in 8-10 min or less if warmer out. The fast idle circuit is unaffected by adjusting the idle speed so if you turn it down the engine won't idle when warmed up. With the engine off, spray the back of the carb with WD-40 or carb cleaner where all the linkages are. Hold the throttle half open and work the choke plate open and closed to loosen anything stuck. Wiggle everything.

 

 

 

A good rebuild kit is $30-$40 and will replace these parts and should have instructions for setting float level, choke, fast idle and others

[Satdun027]

thanks for the replies thus far -
i've already done the carb rebuild - linkages are clean and freely moving, vacuum seems to be in order although i feel like i should go ahead and just replace all the lines - i do not understand the fast idle but it seems irrelevant in a cold start situation - am i wrong about that? 
i understand that the truck needs to idle high when first started - i ran it all winter and spent many minutes in the driver seat smoking a cigarette waiting for it to get up to temp - but this is not the same thing ... unless i have the idle screw up too high? how many turns out is spec? and no i dont have a tach - i suppose i should order one. 

[datzenmike]

You don't have to wait for it to get up to temperature. Start, check mirrors, release e brake and assuming the windows are clear... put in gear and drive. The car will warm up faster being driven.

 

 

Idle will be high while the choke is on. As the choke reduces and turns off, the fast idle will come down. Warm idle speed is set by the idle speed screw and is what ever number of turns needed.