2 Sweet Posted June 17, 2019 Report Share Posted June 17, 2019 Lately I’ve been having an issue trying to get my truck to go into gear after a cold start. '89 Chevy K1500, 350, 4-speed manual w/ granny low. It acts like 1st gear is locked out. Pumping the clutch a few times in neutral and trying 1st again doesn’t work. It doesn’t want to go into 2nd either, and will grind bad if I try to go into reverse. I haven’t tried going into LOW but imagine it probably wouldn’t work either. It will usually go into 3rd with a little extra effort, then I can slip the clutch a bit to get the truck rolling, and at that point I can usually get it into 1st. Then it goes through the rest of the gears fine and shifts flawlessly the rest of the drive in all gears. I drained the fluid from the trans and replaced with fresh 80W-90, made sure it was full, and it made no difference. It only does it after a cold start, and I don’t understand how it suddenly shifts perfect once I get going. It has never once popped out of gear or made any grinding noises or any other signs of failure. So what the hell is going on with this thing? It doesn't seem like it would be a clutch/hydraulic issue, but I really have no idea. I’m stumped. Quote Link to comment Share on other sites More sharing options...
TimTaylor751647545500 Posted June 17, 2019 Report Share Posted June 17, 2019 Have you checked/changed the fluid in and checked the clutch master cylinder? Quote Link to comment Share on other sites More sharing options...
2 Sweet Posted June 17, 2019 Author Report Share Posted June 17, 2019 Have you checked/changed the fluid in and checked the clutch master cylinder? I haven't, and since it's right there on the firewall, I guess it's easy enough to take a look. It certainly wouldn't hurt. I just figure if there was a problem with the master or slave, I would be having issues all the time, not just in the morning when I first start the truck. The clutch seems fine, pedal feels good, the engagement point still feels normal. Quote Link to comment Share on other sites More sharing options...
2 Sweet Posted July 1, 2019 Author Report Share Posted July 1, 2019 You know what's weird? Since the day I made this thread, the truck hasn't had this issue at all ever since. Not even once! It's running, driving, shifting flawless again. Doesn't make any sense, but I guess I don't need to worry about it Quote Link to comment Share on other sites More sharing options...
TimTaylor751647545500 Posted July 2, 2019 Report Share Posted July 2, 2019 You're welcome. Quote Link to comment Share on other sites More sharing options...
2 Sweet Posted July 2, 2019 Author Report Share Posted July 2, 2019 You're welcome. Quote Link to comment Share on other sites More sharing options...
Geeesammy Posted July 3, 2019 Report Share Posted July 3, 2019 I’m not sure if this was the same trans but I had a gmt400 era truck in at work a few weeks ago, it wouldn’t go into anything higher than 2nd, guy swore up and down a rebuild was needed, found that the roll pin that holds the shifter onto the inner bits of the trans that let you switch gears had backed itself out, got a new roll pin, installed it and good as new. Quote Link to comment Share on other sites More sharing options...
2 Sweet Posted July 4, 2019 Author Report Share Posted July 4, 2019 I’m not sure if this was the same trans but I had a gmt400 era truck in at work a few weeks ago, it wouldn’t go into anything higher than 2nd, guy swore up and down a rebuild was needed, found that the roll pin that holds the shifter onto the inner bits of the trans that let you switch gears had backed itself out, got a new roll pin, installed it and good as new. Could've been the same trans, I think the SM465's were available through '91. I think most GMT400's have the NV3500 or NV4500. If the problem didn't correct itself, I was going to remove the shifter and inspect the stub end where it mounts. Luckily it didn't come to that. I still don't understand how it fixed itself, but I'm certainly no mechanic. Quote Link to comment Share on other sites More sharing options...
2 Sweet Posted August 27, 2019 Author Report Share Posted August 27, 2019 Quick update: When I told my brother about this problem, he said it could be the pilot bearing starting to fail. He also said something about checking the bellhousing for cracks? The problem came back a couple days ago, and yesterday I noticed it made a weird noise while in gear at low RPM when the clutch was still engaged. Only did it once, but not a good sign. At this point I think I'll just get a new clutch and pilot bearing, and whatever else it needs. I'm sure it's only going to get worse if I ignore it. Quote Link to comment Share on other sites More sharing options...
Cordell Posted August 27, 2019 Report Share Posted August 27, 2019 Sounds like a clutch related problem to me, or perhaps a pilot. Sounds like the input shaft is getting spun by the engine and not allowing the syncros to work, that’s typically why when the output shaft is spinning (ie truck moving) the syncros can do something. If it a acts up try shifting it into gear with the engine off, if it shifts then it’s almost certainly the clutch or related to the clutch. Quote Link to comment Share on other sites More sharing options...
2 Sweet Posted August 27, 2019 Author Report Share Posted August 27, 2019 Sounds like a clutch related problem to me, or perhaps a pilot. Sounds like the input shaft is getting spun by the engine and not allowing the syncros to work, that’s typically why when the output shaft is spinning (ie truck moving) the syncros can do something. If it a acts up try shifting it into gear with the engine off, if it shifts then it’s almost certainly the clutch or related to the clutch. Yep, when the engine is off it goes right into gear without problem Quote Link to comment Share on other sites More sharing options...
2 Sweet Posted October 4, 2019 Author Report Share Posted October 4, 2019 I had a shop replace the clutch, but I'm worried that the new throwout bearing is bad. It's making a noise and it goes away the moment you apply any pressure to the clutch pedal.... Any chance it's just a cable or something that needs adjusted? It would really suck if they need to take it apart again just because of the damn throwout bearing. Quote Link to comment Share on other sites More sharing options...
TimTaylor751647545500 Posted October 4, 2019 Report Share Posted October 4, 2019 I'd show the video to the shop and see what they say and let them determine whether they need to work on it again. Quote Link to comment Share on other sites More sharing options...
Cordell Posted October 4, 2019 Report Share Posted October 4, 2019 Seeing as how you paid a shop you should take it back. If I had done it in my own truck I’d just live with it, it won’t hurt anything. Matter of fact my last S10 did that. It’s just some extra clearance. One of the benefits to an internal slave on newer stuff, they have a spring to hold the throwout bearing against the clutch. Quote Link to comment Share on other sites More sharing options...
2 Sweet Posted October 4, 2019 Author Report Share Posted October 4, 2019 I'd show the video to the shop and see what they say and let them determine whether they need to work on it again. Seeing as how you paid a shop you should take it back. If I had done it in my own truck I’d just live with it, it won’t hurt anything. Matter of fact my last S10 did that. It’s just some extra clearance. One of the benefits to an internal slave on newer stuff, they have a spring to hold the throwout bearing against the clutch. Yeah, I'll take it back to the shop and see what they think, I'm gonna feel really bad if they have to take it all back apart just for that. The noise didn't bother me at all on that S10, but I don't think I could live with it on this truck especially considering I just paid to get it fixed and it wasn't making the noise before. Quote Link to comment Share on other sites More sharing options...
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