756 starter problem only when cold

My starter will spin fast, but will not engage the flywheel. This only happens when it is cold. I hit the button a few times, then it will engage and start. Notjustair responded to an earlier post about this problem saying that it is gummed up and to pull the starter and spray the gear with brake cleaner and clean it good.

I have never pulled a starter before. Question is: can i just remove battery, remove the 2 bolts holding the starter and clean this gear without removing all wires and outside cover?

My battery is good and I have a maintainer on it when not in use. I do have some corrosion on the posts. I was planning on cleaning them, but, thought I may clean the starter gear at the same time.

I don't recall (or know) whether the 756 starter is the same as the 856 and it's been eons since I saw one of those.

I would disconnect your positive lead from the batteries just so you don't have a wrench ground out somehow. If there is a way I always seem to do it. Leave all of the wires attached to the starter providing there is enough slack to back the starter out. You are going to want it nearly free of the bell housing. Use brake cleaner or carb cleaner to clean the devil out of the gear end, shaft and all (grab SWMBO's toothbrush to get the tough spots). You don't want all of that down in the housing so that's why you pull it away. Less chance of banging your knuckles, too.

Mine was always worse in the winter. The oil seep and dirt would get good and stiff in the cold. I would have to let it whirl a few times and then it would catch. It was pretty grisly in there.

Just for your info. It is always better to remove which ever battery cable is ground when working on something. The reason is that by doing so you can not short any thing out but if the remove the ignition side battery cable you can short out the battery while unhooking it. All the newer manuals say to unhook the ground connection from the battery first

I do not know that tractor as such but for the most part a tractor is a tractor be it older or newer.
#1 you do not need to remove the battery but it is a good idea to unhook the ground side of the battery before working on it.
#2 Yes you should remove the wires from the starter. It will have 1-3 depending on the set up maybe a wire or 2 more just make sure where each wire was.
#3 remove the 2 or 3 bolts holding the starter in and then carefully pull the starter be careful it maybe be heavier then you would think it would be
#4 clean out the starter drive gear area with brake cleaner spray then blow out with compressed air. Then just do as was said just back wards as in 3-2-1

Remove the ground cable as Old suggested on the battery. Check your battery cables for cracks or frayed wires. Replace them if they are. Clean all connections until shiny including where the battery is grounded. Also use a hydrometer to check the specific gravity in each cell. Should be in the 1.275 range. If one reads 1.100 replace the battery. Hal

Sounds like the bendix gear in the starter is worn

If the starter spins and the engine is NOT turning you have a problem with the starter drive. The drive has a one-way clutch built in to prevent the engine from spinning the starter too fast when the engine starts and the drive is still engaged with the ring gear. You need to remove the GROUND cable first, then remove starter and replace or have somebody replace the drive. This old one-way clutch is not locking up to turn the flywheel.

Safety note.. When working with batteries around tractors, you ALWAYS want to remove the GROUND cable FIRST. If your wrench touches the frame when removing the cable you will not get any sparks. When connecting the cables back up, always install the GROUND cable LAST. This does not make any difference if you are dealing with a neg. or pos. ground system. You just have to check which cable is connected to the frame for ground.

The starter on a 756 does not use a Bendix style drive so it does not get stickie.

Let us know what you find.

My 756 Int. has twin 6 volt batteries; The best /easiest access is from the left side, but you will need to remove the battery on this side, (ie) the positive post and negitive post cables should both be disconneced.

That starter looks real easy to get out of there, til you get it loose. There was a trick to it but I can't remember it. My uncle had it out of the one we had every winter for a few years, til we replaced it instead of rebuilding it.

Thanks to everyone for responding so quickly. I posted the message and was gone all day.

I am confused on what to do to solve this issue. I looked at the starter drive from this sites link (Starter Drive Part Number 1877350), it looks like it is a bendix style drive to me.

This problem only happens when the temp drops to 35 and below. I never seem to try to look into when it is warm, of course! It really seems to act like something is sticky and not engaging. I did replace the solenoid a couple years ago..and it seemed to help for a while.

I will definitely clean up the battery posts and inspect the connections tomorrow. I don't have a hydrometer to test the cells, but, it seems to turn the motor fast when it does engage.

Is there a trick to pull the starter off, like T in Ne mentioned? I don't want to get it taken off an not be able to get back on. It looks straight forward. If it is, I may try to remove to see what is going on. Just don't have tons of time to devote to it right now...

Thanks again for the advice.

I went and looked up the picture of the starter drive that you talked about, 1877350 is the correct drive. That drive is not a true bendix drive. The old A, B, C, H, M 300, 400 series of tractors, just to name a few, use a true bendix drive. Lots of people call all starter drives a bendix, but there is a difference.

I was able to find a picture of the bendix drive. When this drive gets dirty and covered with old grease and oil it will not work when it's cold. This style of drive gets sticky and needs cleaning and a very light lube. I like to just spray with a good penetrating oil.



A true bendix drive screws it's self into the flywheel ring gear. Starters that use a true solenoid use a magnetic force to pull or shift the drive into the ring gear before the armature starts to turn.



Your starter drive is wore out, when you pull the starter out, take your fingers and turn the drive gear, if you compare it to a new drive you will see the difference in how loose the gear is. Good luck, keep us posted.

Only happen when cold say the starter drive or as call bendex is grease/oil cover so when cold the grease/oil is thick and hard to move so the drive does not spin out like it should. Good chance a good cleaning will help/fix the problem or get you by till the weather get warmer. To me an easy fix but then I do tractor repair day in day out as a hobby

A 756 does not use a starter that depends on inertia to engage like the letter series tractors do. Instead it uses a drive that is shifted into place with a lever controlled by the solenoid. If that type of drive does not crank the engine while the starter motor is turning there is a failure of the clutch in the drive just as charlieu has posted. Replacement of the drive is the only way to repair the starter. Unless some has recently repaired the starter without replacing the drive, when you get the starter apart you are going to find it needs more service than just replacing the drive.

Since you have not said whether the tractor your are posting about has a gas or a diesel engine I'm going to assume that you have a diesel since you came up with 1877350 as a replacement drive number.

There are several drive numbers that will work in your starter. The original drive for the diesel starter is part number 1948877 which is a roller clutch type drive. That number has a little heavier roller clutch than number 1933838 which was used in the 706 with the D282 engine. Part number 1877350 is still a roller clutch type drive but it is heavier than the other two numbers listed here. It is the drive that was used in the 66 series gear drive tractors.

The 1066 Hydro used drive part number 800965. This drive has a spragg type clutch rather than a roller clutch.

There is one other type of drive that can be used. It uses a ratchet type clutch. I don't have a Delco part number for it. I'm not sure if Delco even built one like it. My supplier part number 5002GN but SDR5076 is the same drive from another vendor. In both cases they list it as a replacement drive for part number 1877350 even though it has a different type clutch.

Sorry, not only did I not give you enough information, but, also gave some wrong info too. It is a '67 756 gas.

Thanks for the education regarding how the starter drives work for this. I don't think I will mess with pulling the starter until spring since I have bad thoughts of hand scooping the snow in the lane if I mess it up! My 7 year old triplet boys probably won't help enough... lol.

One thing that I still don't understand is why does it only stop working correctly when it is cold? This never happens when it is warm. Is it just because the cold slows down the current?

I am heading out in a while to clean up the battery...hopefully, this will help some.

Thanks guys.

If it is because the starter drive has grease/oil on it. Then it happens due to the fact cold grease/oil is stiffer then warm grease/oil.

I cleaned up the battery and the cable connections. I put on those felt washers and spray on stuff to stop corrosion. I also took the cables off where they hook to the solenoid and starter for ground and used emery cloth to get them shiny. It actually seemed to make it worse...it took more tries to get the starter drive to engage.

Looks like I may have to get it fixed before spring time. Will it just suddenly not work at all...or will it just take longer and longer to engage?

You need to replace the drive. The one way clutch is not holding when it gets cold.

It is too late for it to "suddenly" stop working. It is already giving you its warning that it is failing.

The information I posted earlier for diesel engine starters mostly applies to the gas starters also. The drive gear is still a ten tooth gear but it has a smaller OD. The part number is 1851427. If it has been replaced before you may find a nine tooth drive gear (part number 1939109) since that drive was used in earlier gas starters. Use the ten tooth gear for replacement. It will last longer.