About ATR gearbox... ...5th gear problem

[hondaddict]

Hello everybody !

I've opened recently a U2Q7 gearbox and here are the pictures of what i've found Inside:








I didn't take a picture of the synchro hub but it is also damaged.

I've take a look at the spares parts i have and i noticed that the gap between the hub and the sleeve is bigger on ATR parts than on Prelude/Accord parts i have.
It also seems that an excess of gap between these two part can be the cause of the problem.

I don't know if someone have already search what is the real problem with the ATR 5th gear but it may be an possible answer

[Craig_85]

Thanks for posting this. Honda issued revised parts when fixing atr boxes, quite possibly for the reason you have identified.

I've not seen inside a damaged u2q7 before but I have caused the damage from the driving seat!!!

[RattyMcClelland]

It's the selector folk that's the issue. It's not strong enough and gets weak over time meaning 5th gear at its longest reach doesn't fully get switched.
Strengthening the folk help. Performance Autoworks did this.
That's the accord selector folk.

[hondaddict]

Thanks for the input , mates!

About the revised parts, if someone have the part number it will be great!

About the selector fork, i'll take a look at that, as i also have spares selector forks , i'll see where is the difference

Ratty, do you have a picture of the strenghtened fork?

[wurlycorner]

Great pics - it's always interesting to see what's the cause of problems like this.

[hondaddict]

Thanks Wurlycorner

I believe it may help to satisfy the curiosity of those who Wonder what is the problem...
So, when the synchro sleeve is damaged, the 5th speed becomes harder to be engaged, as the reverse speed ... the same sleeve is used for the both speed

It is very Strange to see that kind of problem on a gearbox desing realeased nearly 10 years before , i Wonder if these involved parts have been made by Honda or someone else

edit: after reading an interesting post on another forum , it seems thatit is a really "old" problem

http://www.preludeonline.com/f91/manual ... on-104769/

I'm not really convinced about the "fork" explanation, i truely believe that the problem is somewhere else.
The gap between the synchro hub and sleeve is probably a cause, another problem is the size of the teeth of the 5th gear synchro, really too small.
Compare the teeth of the 5th gear synchro with the teeth of the other synchro and you'll see what i'm talking about