Topic: 1st gear pops out

[kornesque]

1st post, thanks for having me aboard.  before i go any further, i've already slapped in a MC shift lever seat assy, and although it's more positive overall, i'm having the issue still - 1st gear pops out when the clutch begins to engage. here's a brief of the problem...

when the truck's just idling, clutch engaged, i can hear a whiring sound which goes away when the clutch pedal's depressed about 3/4 way. i'm guessing this is normal, since my previous 5spd did the same thing. i figured it wouldn't hurt to try adjusting the freeplay, so away i went. i was only able to extend the pushrod maybe a 1/4", which did change the point where the "whiring" sound let off by a bit, but not much. a quick test revealed negative results as far as fist gear staying engaged at clutch.

so my symptoms at this point are:
1) 1st gear pops out when clutch begins to engage, ~90% of the time. acceleration is smooth throughout the range as long as my hand keeps the shift lever in place.
2) 2nd gear is sticky getting into and out of, not too bad but noticeable. all other gears are relatively smooth.
3) at any speed over ~3mph, 1st does not want to engage, no matter how depressed the clutch pedal is. awful grinding ensues unless i'm at a near stop.

i have not tried bleeding the hydraulic circuit yet, due to the fact that gears 3-5 work fine. is this bad logic? any assistance on this would be MOST appreciated. i'd like the keep this issue as DYI as possible, although my scope of mechanical expertise is limited. i've learned a lot by reading thought all these posts, but i still have no hands on. THANKS!

[79coyotefrg]

unfortunately  this  sounds like  the transmission needs to be rebuilt

what  year  truck  and    to Marlin

[kornesque [OP]]

i can't believe i didn't mention...'95 3.0 V6. so it sounds like the tranny rather than clutch huh? i'm sure it's hard to guesstimate, but how long do you reckon i can expect to deal with the issue before it gets catostrophic? is there any non-intrusive fault isolating i can do to narrow it down, or would it all involve getting in the guts? appreciate the assist.

[Tallchevy]

Sounds like the shift collar is worn.

[kornesque [OP]]

that was one of my theories too, since it only affects 1 and 2. either that or maybe bad synchro hardware. the thing that puzzles me is that all's well if i keep it in place by hand. either way, still looking like the tranny's coming down, please keep the great ideas coming, most appreciated. hopefully with your help i can get this narrowed down to prevent wasting funds. 

[dt]

the symptoms you are reporting indicate more than one problem with your tranny itself,when you have your tranny out you can inspect your clutch stuff and rectify those problems at that point,then it goes back together ALL GOOD

[highridin4x4]

My tranny did the same thing but it was 1st and 3rd. This is what I found. My tranny is a W56B I am not sure what model yours is but I am sure it is similar inside.

Here is a picture of my mainshaft and gears.

 

The bearing at the bottom of the picture I call it the center housing bearing was worn out causing the whole shaft to move inside the tranny when you put it in first or third gear. As you move the shifter forward inside the tranny it moves the shift collars back over the brass syncro on to the gear. If the bearing is worn out the shaft moves further than the throw of the shift collar ( thats why its fine if you leave your hand on the shifter) witch does not fully engage the holding keys of the shift collar.

Hears a some pictures of my worn out bearing

 In this picture I am moving the inner race with my finger to show the play it had. It should not have moved at all.


This one shows the wear itself on the races. They should be smooth not pitted.



Oh welcome to the board  

Scott

[kornesque [OP]]

wow. VERY informative, at least for me. mine's a R150F, from what i've gleaned in my mostly useless haynes manual, there are some minor differences, but i'm sure that bearing is quite standard. it really seems it must come down, so i guess i should go ahead and start my homework. or get a side job and find a good mechanic.  thanks VERY much for the illustrated input.

[highridin4x4]

Your welcome you can get a heavy duty bearing kit from marlin or get a rebuilt one from them and send them your core. I rebuilt mine and I did have to use a press and some heavy duty pullers to get the gears off. I would get marlins bearing kit if you are going to have it rebuilt yourself.

Scott

[boggerunner]

i have a good 90 v6 tranny for sale in co if u are interested in just replacing it, i only want $250

[kornesque [OP]]

@boggerunner, i'll keep that in mind if it turns out it's what i need. your rig sig suggests it's a w56 - i have an R150...are they compatible?

on another note, i just spoke to a gearhead aquaintance i almost forgot i had. after describing the problem, he seemed pretty certain it needs a throw alignment, acomplished somewhere around where the internal shift lever harware is. he says tranny shops can do it in around an hour (the tool runs ~$300). has anybody heard of this, cause i sure haven't. if so, would it be worth a shot? thanks again.

[boggerunner]

i put a 22re into my 4runner with a w56 and duals, i hate the v6's so all my v6 crap is sittin in the corner of my garage takin up space, and it is a r150

[RN37DD]

i had a hell of a time with my 94 4runner r150f tranny. some times it would not shift into first and other times it would pop out of first,..  the tranny had just been rebuilt before we bought it for $1800.00 so i couldn't believe it was bad. i pulled it apart and found the 1st gear shift fork retaining bolt had not been lock tight or torqued.  new bolt and torqued and I'm still driving it today. it's a 2 dollar bolt.

[kornesque [OP]]

ugh. helluva task in relation to the problem and cost of the part. all the ideas still point to inside the xmission, so at least i have better ideas of what to check. thanks for the input!

[weirdtimes_7]

Sounds like the shift collar is worn.

This was my first thought

military_stang

[jonesota]

the  one out of 1000 times my trany popped outa first gear i was on a hill with a tree realy close to  me and i smashed into it

[79coyotefrg]

, he seemed pretty certain it needs a throw alignment, accomplished somewhere around where the internal shift lever hardware is. he says tranny shops can do it in around an hour (the tool runs ~$300). has anybody heard of this, cause i sure haven't. if so, would it be worth a shot? thanks again.

i have heard of this but on a automatic trans, 

the r150F  is a manual  and  of a  shift fork  or  collar is  bent or  worn out it needs to be replaced

[RN37DD]

not to freak anyone out. but the shift forks on the r trannys are aluminum. instead of bending they get chewed up and brake when things go wrong with them. the collars are steel and will eat the forks without even hardly wearing if  the shift is forced to much. the forks are only held on the shift shaft with a single 6mm bolt.

[boggerunner]

my buddy killed his r154 cause he forced into gear, and killed the shift fork, it was also aluminum, and busted some chunks off of it

[RN37DD]

yeah i believe the story on the above r151. was the dude was using his overloaded toy in deep sand and forcing it into gear with no clutch. 

[84solidaxletoy]

shift fork is junk. mine did that. had almost 300k before needing to be rebuilt. my shift fork was toast. i had to keep full pressure on it or it would pop out. it got to the point that even on inclines it would not stay in even with full pressure. it was almost paper thin when i replaced it...needless to say i am 99% that she is done for