Overrunning gear/sungear the same thing?

[Shadow]

Neibour put her Caravan into reverse, backed up, made an awefull grinding/metal/gear chewing sound, put it back in drive and pulled back into her parking spot. I went over to check it out and van won't move forward or reverse and sounds like gears trying to engage but chewed or something.

This is the 3 spd auto, I think it's a 98 caravan, so Not the 604. Tried pulling it backwards and front tires were locked, but it did pull forwards to the shop. Dropped the pan, picture tells the rest of the story.

I'm guessing that's what's left of the overrunning gear (sungear?) lying in the pan?

[Vigo]

Those rollers are too small to be the ones from the sprag ( /overrunning clutch). They look like needle bearings like what you find in the planetary gears.. I havent done trannies in too long (use it or lose it ) so im pretty rusty on it anymore but im guessing one of the planetaries is fragged. It definitely needs to come completely apart.

This might help.
https://www.wittrans.com/Schematic.a...70&Schematic=2

Also i can email you the PDF of the ATSG rebuild book for the 413 if you want it.


There are a couple of terms people use for the same thing.. overrunning clutch, one way clutch, sprag can all refer to the same thing. The 413 only has one and it is only active (holding) in 1st gear, the rest of the time it is spinning (or overrunning). When the sprag dies you will lose 1st or have a slip in 1st, but you can usually put the shifter in the 1 position and get it to work because then the low/reverse band will take over the sprag's job. Its a weird coincidence of the design that 1st gear works differently whether you are in drive or manual low (1 or L on the shifter).

A sun gear is the inner most gear in a planetary set. The sun is in the middle, the planet gears orbit the sun, and the ring gear is outside the planets. So any gear in the middle of a planetary gear set is a sun gear. The 413 has 2 sun gears, but they are made onto the same part so it is really only one piece that has two sun gears on it. There could be pieces of a sun gear in that mess right there because once a planet gear goes it takes out the sun gear and the ring gear with it.

Good luck letting your neighbour down easy..

[135sohc]

Edit:

I was going to say those look like the little wavy springs in the sprag but its just the way they are stacked up. How many miles/KM's on it ?

[RoadWarrior222]

My thoughts are, i) yup looks like a bearing, and ii) is any of that small stuff non-magnetic, silvery grey case casting looking stuff, because if so, it probably carved up the bearing seat of a shaft in the case and you'll probably wanna get another A670.

The good news is that dropping trannies out of vans is a piece of cake.

[Shadow]

Those rollers are too small to be the ones from the sprag ( /overrunning clutch). They look like needle bearings like what you find in the planetary gears.. I havent done trannies in too long (use it or lose it ) so im pretty rusty on it anymore but im guessing one of the planetaries is fragged. It definitely needs to come completely apart.

This might help.
https://www.wittrans.com/Schematic.a...70&Schematic=2

Also i can email you the PDF of the ATSG rebuild book for the 413 if you want it.


There are a couple of terms people use for the same thing.. overrunning clutch, one way clutch, sprag can all refer to the same thing. The 413 only has one and it is only active (holding) in 1st gear, the rest of the time it is spinning (or overrunning). When the sprag dies you will lose 1st or have a slip in 1st, but you can usually put the shifter in the 1 position and get it to work because then the low/reverse band will take over the sprag's job. Its a weird coincidence of the design that 1st gear works differently whether you are in drive or manual low (1 or L on the shifter).

A sun gear is the inner most gear in a planetary set. The sun is in the middle, the planet gears orbit the sun, and the ring gear is outside the planets. So any gear in the middle of a planetary gear set is a sun gear. The 413 has 2 sun gears, but they are made onto the same part so it is really only one piece that has two sun gears on it. There could be pieces of a sun gear in that mess right there because once a planet gear goes it takes out the sun gear and the ring gear with it.

Good luck letting your neighbour down easy..

Thanks for the splanation, I'm no expert when it comes to auto's so every bit of info counts.

---------- Post added at 02:21 PM ---------- Previous post was at 02:19 PM ----------

Thanks for the replies guys, I'll look but I'm pretty sure this ones reaching the 400 000km mark. Tells me what I need to know anyway, Not going to be servicing it in vehicle!

[bakes]

bye bye planetary"s

[turbovanman²]

Not sure where the needles came from as those seem large, the planetaries are smaller from what I remember but in reality, that thing will need to be completely overhauled and probably most parts replaced, so if she wants to keep it and is on a budget, find a good low K used one.

[Shadow]

Not sure where the needles came from as those seem large, the planetaries are smaller from what I remember but in reality, that thing will need to be completely overhauled and probably most parts replaced, so if she wants to keep it and is on a budget, find a good low K used one.

Dats the plan. I just wanted to confirm (to her) wether or not it was major or minor and what her best course of action would be.

Thanks again guys!

[RoadWarrior222]

BTW, peek in the diff cover... if it was the diff bearings, you miiiiight get away with cleaning it out and putting a "new" diff in there... or you might not.

[Shadow]

Could the diff bearings transfer into the pan like that? I figured they would be somewhat confined to the diff? (ie. not enough room with the ring gear and pinion to pass by)

Also, and as I stated earlier, vehicle will roll forward Only. Pulled it back to get it out of the shop and left two black patches before putting it on wheel dollies to move it. Was thinking possibly diff pin engaging the case one one way rotation, but I would have thought it would be opposite. Diff pin eats case forward, but can still reverse. I would also think that if the pin fell out and ate into the case this far it would have blown it apart already.

[turbovanman²]

I would bet the rear planetary let go, don't listen to RW, there is too much crap floating around for a quick fix, either complete overhaul or cheap replacement,

[RoadWarrior222]

Yeah, it would be unusual to get a whole lot of diff parts in the front there, but then, it looks like not quite a full set and the race/cage metal isn't there yet either. I wasn't thinking so much about the middle of the diff as the ends.

[Vigo]

Those rollers are still way bigger than whats in the pan. Also i agree with turbovanman that this case calls for a completely new trans as that kind of debris means MOST of the parts in the trans will have been damaged and need to be replaced. Cheaper to start over with a different one.