I have a 06 H3 Adventure series with a manual transmission. In the past I have had issues shifting into 4th, mainly on the downshift but I found that bumping it into 3rd then back down into 4th worked fairly well. I assume this is probably a syncros issue but it hasnt been enough of a nuisance for me to worry about it. It has also given me some difficulty shifting out of reverse at times (it would stick in reverse) but that is also something I can deal with.

Recently it has started jumping out of 1st gear whenever I start letting out on the clutch from a complete stop (it may do it from a rolling stop too but I havent noticed). With me commuting everyday this has become quite an issue. I don't even want to drive out of town because I'm afraid my trans might be going out. Also, it clunks fairly loud when shifting and it kinda feels like its not fully disengaging. I've noticed when I have it in 4-lo, shifting from neutral to 1st will engage just a little even with the clutch pedal all the way down. Anyone experience these issues on a manual trans before? Any suggestions? Thanks for the help!

 

how many miles on it? You might just need a new clutch and slave cylinder.

 

It appears your trans is on its way out. R&R time. GL

 

Sounds like you are going to need new synchros and gears. If you have the work done do all the gears and synchros, a mismatched set of gears will whine like crazy and drive you nuts in short order. A poorly adjusted/bled clutch could have been causing some of your issues.

 

Just rolled over 120k

 

Just checked with a local mechanic and got a quote for around $2,100 for a rebuild with a 3yr/36k mi. warranty. Not a dealer but a ASE certified GM master tech. Does that sound like a good price or should I call a few more shops?

Looks like I could pick up a low milage transmission for a Chevy Colorado for around $500-800 and just replace it myself. Anyone replaced an H3 trans yourself? Any gremlins I should know about doing a trans swap with a colorado trans? Thanks!

 

Don't know about the swap, too lazy to research it but someone (Bunger? Tainter? ) just recently posted the differences and high points on the Aisin transmission on a different forum. You might find ratios are different as well as not as beefy.

The price doesn't sound bad if its 100% gone through. You can pay less but somewhere someone will have to shortcut something.

 

when you are shifting into 3rd from 5th you are spinning your transmission internals up


if this solves your shifting into 4th problem everytime i would guess your 4th gear synchro is going out


tries this out

clutch in



get to neutral

clutch out

rev the motor to what your rpm gonna be after shifting to 4th ( a little bit higher )

clutch in

shift into 4th ( do the last step very fast)



if it goes in smoothly , well that means your synchro is out

i am in no-way an expert but hope this helps somehow

 

I recently replaced the clutch and slave cylinder on my H3. It had about 120k miles on it. Cost me about $1,200 at an independent mechanic (using all original GM parts). Not too bad considering its the only major service I've had on it in 8 years.

 

you may try clutch fluid bleed and swap it could help