98 International 4900 shifting prob.

[asetree]

Manual transmission. Having trouble with the shifter. This truck is a seven speed, setup like this:

R 1 3 5
| | | |
L 2 4 6

From what I can gather this thing has a spicer transmission that is syncro-ed.

All the gears R 1 3 5 work fine, 2 4 and 6 six tend to want to fall out of gear,
Fall is the best way I can describe it, as they pull fine and seem to shift in to gear OK, but when you hit a bump or decelerate too quickly they just sort of fall back to neutral.

I am pretty new to this truck, anyone had a similar experience?

Thanks,
A

 

[Rookie1]

Never had anything like that happen but from looking at your diagram I would say its with the shifter more than the trans. Have you checked all the basics,bolts tight on bellhousing and shifttower.Check trans mount too.

 

[TDunk]

How many miles are on the truck ? When you say "pull fine", do you mean pull fine into gear or pulls hills fine with out popping out of gear. The first thing i can think of is that detent springs are probably bad (broke or weak) Not to bad to fix.

 

[asetree]

100k on the truck. Pulls fine, clutch not slipping and works fine as long as I sort of hold the shifter in place.
A

 

[sharkfin12us]

shifting

Manual transmission. Having trouble with the shifter. This truck is a seven speed, setup like this:

R 1 3 5
| | | |
L 2 4 6

From what I can gather this thing has a spicer transmission that is syncro-ed.

All the gears R 1 3 5 work fine, 2 4 and 6 six tend to want to fall out of gear,
Fall is the best way I can describe it, as they pull fine and seem to shift in to gear OK, but when you hit a bump or decelerate too quickly they just sort of fall back to neutral.

I am pretty new to this truck, anyone had a similar experience?


Thanks,
A

I have a 1998 4900 international same set up shifting as you.I would take it to international shop near you.I have had other truck places work on my truck only to have some rookie working on my truck get it back some thing leaking not put back right or what ever.Now i just take it to international and works for me.Have it checked out.Im the only one that drives it and i have 77,000 on it when i bought it had 56,000 hope that helps.I dont know the terms but it could be the fingers that hold the shifter in place are worn.As someone stated might not be that expensive

 

[Rookie1]

This is kind of a joke but I knew a guy that was pretty cheap and I would imagine he would have rigged up a bungie cord from the seats to hold the shifter back. That way you wouldnt have to hold it.I wouldnt do that but Ill bet its been done before.

 

[B-Edwards]

We had a 1976 5000 ford tractor bought new and used it to level and pack silage in a trench silo. I usually operated the tractor but this time my dad put another fellow on it. He was lazy on the clutch and as you are going back and forth back and forth back and forth all day long he bent the shifting fork so it wasn't meshing the gears up as they should have been, you had to hold it in gear by force. I don't know transmissions only what happened to ours but it sounds similar.

 

[tree MDS]

My guess is the syncros are shot for those gears. Its usually from some a hole grinding gears I believe - I could be wrong as I dont know too much about the bigger trucks.

 

[woodchux]

I use to have a small nissan truck that would pop out of first gear...It started to act up after i had the transmission rebuilt and the fellow bent the shift fork taking it apart.

 

[TDunk]

If it wasn't gears 2,4,and 6 I'd say it could be a synchro. prob (and it still could be) it's just seems odd that those three synchros. could be bad and all 3 shifting points are on the bottom side of the stick. We had a Mack in our shop (with a Mack tranny) and it would pop out of any gear in low range. So it is a possibility. A bent shift rod (that hold the shift forks in place) could cause that too.

 

[ASEMASTER]

detent

first has the tranny been out before? they use springs and detent balls to hold the shift rods in place, they are on the top side of the case all you need to do is take off the top and check it out. at the same time you can see in the trans to check for other possible bent shift forks or bad sync.

 

[DanManofStihl]

To me it really soulds like a synchro problem. Our old roll back wrecker had the same problem with 3rd and 5 gear. Not a cheap fix either unless you pull it and replace your self.

 

[asetree]

I like the dentent theory so I will go with that. Keep your fingers crossed for me. When you say take off the top you mean the shifter "tower", with the shifter sticking out of it? Does it just unbolt and pull off? Should I watch out for springs shooting out and dropping into the tranny? Any other things to look out for? I have taken the shifter off the top of a toyota pickup tranny, is it just like that? Take off the shift boot, unbolt the tower and pull up?

Thanks for all the responses.
A

 

[TDunk]

I like the dentent theory so I will go with that. Keep your fingers crossed for me. When you say take off the top you mean the shifter "tower", with the shifter sticking out of it? Does it just unbolt and pull off? Should I watch out for springs shooting out and dropping into the tranny? Any other things to look out for? I have taken the shifter off the top of a toyota pickup tranny, is it just like that? Take off the shift boot, unbolt the tower and pull up?

Thanks for all the responses.
A

You got it. There should only be 4 bolts (9/16 head i think) and it should lift right off. You might have to persuade it a little because of the gasket.

 

[grandpatractor]

If it is like I remember you can take off the shift tower, but there is a plate rivetted on top of the tranny that holds the spring and detent balls in. The rivets have spiral grooves. To get them out you may be able to use a cut off wheel or file to make a flat spot on the sides, so you can get a hold of it with a visegrip. If you break them of you will have to drill them. Just put a magnet next to the drill to catch the filings. If the springs are fine them you'll have to have the tranny rebuilt. Usually the shift collars are worn out but you may get lucky and find a broken or weak spring.

 

[asetree]

Grandpa: sounds like you are say I would have to have the transmission out to check the detent springs?

Is it even worth pulling the shifter? what would I be looking for?

Thanks for all the help!!

 

[grandpatractor]

I was able to do the work thru the floor of the cab to do the detent springs under the shift tower. If the detent springs look ok then its time to pull and go thru the tranny.

 

[TDunk]

Grandpa: sounds like you are say I would have to have the transmission out to check the detent springs?

Is it even worth pulling the shifter? what would I be looking for?

Thanks for all the help!!

You'd have to pull the shift tower anyways to pull the tranny so...... It's not really a waste of time.

 

[lxt]

How many miles are on the truck ? When you say "pull fine", do you mean pull fine into gear or pulls hills fine with out popping out of gear. The first thing i can think of is that detent springs are probably bad (broke or weak) Not to bad to fix.

#1, trucks at the utility use to do this.......weak/broken de-tent spring!! cheap six to start with too.


LXT.................