Reverse Grinding, not normal!

[ifish4tuna]

Hey 1st post here. Just passing along some intel and a service recommendation.

I was searching about gears grinding when putting my Civic in reverse. I am a multi honda owner driving nearly all of them to 300K miles, and buy them for reliability reasons, and ease of maintenance when needed. I buy all of them used with 60-100K miles.

I'm planning to drop off my 2004 Civic EX with 98,000 miles to my son in North Carolina in the near future. It will be replacing the 2004 Civic EX which has 296,000 miles, and is now leaking oil considerably and not worth the extra $/work to resolve.

Prior to delivering I wanted it in tip-top shape. The car had been grinding when putting in reverse more and more. I bought it with 62,000 miles used 1 year ago. It had the problem then, but has progressed to be very frequent. Like 4 out of 5 times. I can avoid as has been discussed on this forum and others, but going into first, then reverse, but who the heck remembers to do that? Only after hearing the grind.

It has also been discussed on this forum and others, that this is normal behavior for Honda's because they don't synchronized. That's BS. The car down in NC w/ nearly 300,000 miles has never had a problem grinding when putting in reverse.

I brought the car to my local AAMCO in Portsmouth, New Hampshire - Service Manager's name is Paul, and after considerable diagnostic, they have identified it is a linkage issue. Paul sent me a picture of the lever showing the visible wear. There is a part that it engages with that is also worn. Once photopbucket comes back on line I will post the picture. Paul and his mechanic also confirmed (as did my local Honda dealer), that there is a synchronization gearing which should avoid the grind.

As a note, I HIGHLY recommend this shop if anyone needs service. They are thoughtful, honest, and have integrity. At the end of the day I dropped it off, while still a puzzler, they spent 15 minutes with me going through the diagnostics with me showing me the tranny on the bench.

I give this AAMCO shop an A+ rating.

Ed

 

[ifish4tuna]

I'll update once I receive the car back. Parts on 2 week back order. I have another car to drive (1999 Lincon Town Car) while out of commission. I'll also post the pic of the worn part after photobucket.com comes back to life.

 

[XpL0d3r]

It has also been discussed on this forum and others, that this is normal behavior for Honda's because they don't synchronized. That's BS. The car down in NC w/ nearly 300,000 miles has never had a problem grinding when putting in reverse.

It's actually not total BS, though. It depends on what transmission you have. IIRC, it uses the 5th gear syncho set to stop the mainshaft. When that syncho is worn, it mushrooms out - you can still shift into 5th fine, but the syncrho gets in the way when shifting into reverse, hence the grind. You can align reverse by putting it into 1st or 2nd gear first. Both my D16 and B18 transmissions did this.

Right from a 96-98 service manual:

Whenever the clutch pedal is depressed to shift into reverse, the mainshaft continues to rotate because of its inertia. The resulting speed difference between mainshaft and reverse idler gear produces gear noise [grinding]. The reverse gear noise reduction system employs a cam plate which was added to the reverse shift holder. When shifting into reverse, the 5th/reverse shift piece, connected to the shift lever, rotates the cam plate. This causes the 5th synchro set to stop the rotating mainshaft.

Also, you can use other sites to upload photos. Imgur, postimg, to name a couple

 

[ifish4tuna]

Yah, thanks for that. I should have been more precise since precision matters for people looking at these forums for accurate advice. The point being, perhaps some of the trannys require the "go to first" before reverse, but likely not all. Thanks for adding clarity. And what's happening on mine is that linkage is worn preventing the full engagement. The shop showed me the piece that's meant to slow the gear prior to engagement.

Ed

 

[XpL0d3r]

As far as I know, no D-series transmissions have a reverse synchro. Which makes sense -- the point of a synchro is to match the speed of the mainshaft to the gear. With reverse, you're not supposed to be moving at all, so there's no speed to match. Putting a reverse syncrho in there isn't really needed.

 

[ifish4tuna]

 

[ifish4tuna]

I don't know the exact part. But they said they were replacing the one in the picture and one more also showing wear that this part meshes with. At the end of the first day I left it there after it had been torn down, and then reassembled, I visited during the end of the day. They showed me when moving through the gears (assembled) on the bench they could periodically get it to not fully engage, but was not clear why. Unfortunately, they had it apart inspected everything, head scratched, reassembled, and then had to take it a part again and eventually found the linkage. Service records show original owner had done a clutch at 35K miles. Don't know why - probably juvenile driver, and perhaps the reinstall wasn't done properly again don't know....

It clearly needed a clutch, also the fluid levels were down a bit. I asked him to send me a picture of the other planned part also, but have not received it yet.

Now that I've spent (wisper voice - too many hours at work) researching this, I have a better handle on the inner workings, and now understand why so many said no sycnro on reverse due to being a straight gear, but still don't agree with grinding being normal and requiring going to first before reverse. It's clearly a symptom of another problem.

I have had a hard time finding anything on the linkage specifics which moves the idler gear.

They are going to charge only for 4 hours labor (original disassembly + the 2 Parts, + plus the clutch =1200. Probably have close to 12 hours into it already.

Again, a shop w/ integrity.

 

[ifish4tuna]

Thanks. I have the $ breakdown written down at work. Clutch was 845 of it including parts. Do you see which part # in the diagram is the picture of the part I posted?

 

[ifish4tuna]

Here's the part that was replaced. Not bothering w a pic of the other part that it mechanically moves because this one is the root of the issue.



Problem solved. Clutch and all gears smooth as butter. I still assert that grinding when going into reverse should never happen. I'm more than satisfied with the results, and the cost is worth it to me. I will drive this vehicle to over 300,000 miles like I do all my Hondas. This one is just broken in at 98K miles.

Parts involved :
Clutch assembly
Flywheel resurfaced
Shift reverse selector
Shift reverse link
New Seal Set
Fluid
Shop Supplies
Labor.

I will bring it back in 10 days to inspect for leaks or any issues.

Ed

 

[ifish4tuna]

Yes, agreed. Not sure what would allow for the deviation to begin to occur on that part, perhaps the bolt not secured properly. Will never know for sure. Glad its working now though.

Happy Thanksgiving. Enjoy your family.

Ed