Reverse gone?

[kaptainballistik]

Well, the car was always "Snicky " for 5th and ground Reverse a little. During the last rally the car stated constantly popping out of Reverse.

Coming off the trailer it would pop out as soon as the Cluch started engaging. The shift cable is bowing when you try to engage reverse. Im thinking reverse syncro has broken or the shifter bracket has gone and got wonky.

Does that sound like what I have? ( Never poked around a VR4 "Box") I dont think its the old 5th gear falling off trick as the gearstick is as steady as a rock. Or could it be a fork/Hub has crapped out?

Just need to know what im looking for ( Stealth repair...in Mums gararge for storage :hide: )

 

[14u2nV]

maybe teeth on the reverse idler are worn off, otherwise I'd think bent fork maybe

 

[Telecaster]

I have the exact same problem. 5th and reverse are totally gone sometimes. But when running, i can go into 5th no problem.

 

[Barnes]

Honestly I think this is common. I think the reverse cone brake (basically a syncro but not quite) sucks. It never seems to do its job of stopping the input shaft completely before I try to put it in reverse. Thus the grinding noise.

So what happens is the reverse idler, input shaft, and 1st-2nd slider(has gearing on the outside that the idler engages with it) start to wear the engaging side of the teeth. These teeth are initially pointy so the teeth don't have be perfectly aligned when you start to engage them. After grinding enough times, the gears start to become squared off where they used to be pointy. So you get these situations where the gears will not slide together unless the teeth are perfectly aligned. Thus, the bowing of your reverse cable. You are trying to force something together that just won't go. You are have to rotate the gears very slightly to get them to go together.

How do you do this? Easy really. Option 1: Pull the shifter so you are trying to go into reverse, hold it there with your hand. Firm pressure, but nothing crazy. Then very slowly let the clutch out enough till it gets to the engagement point. This will cause the input shaft to rotate just a tiny bit, which is almost always enough to get everything to line up enough. The shifter should then slide into reverse. Option 2: With the clutch in, shift the tranny into other gears and try reverse again. Changing gears will slightly change the orientation the input shaft in the tranny possibly letting you slide it into reverse.

As for popping out, you're only choices are to either hold the shift lever in reverse as you use it. Or get into the gear box to fix it.

Only sure fire way to fix this problem is to get into the gear box, replace the reverse idler, 1st-2nd slider, and perhaps the input shaft if the teeth are really worn. Although I think the input shaft does better because I think it is a harder material.

To help prevent this in the future: I recommend a couple things. Wait a few seconds after pressing in the clutch to shift into reverse. This allows more time for the input shaft to come to a stop, thus preventing grinding. Other option is to shift it into 1st with the clutch in, then shift into reverse. Shifting into 1st stops the input shaft by using the 1st gear syncro. This does the same thing as the first recommendation, just a tad faster.

 

[Hertz]

Some cable adjustment might help as well. Make sure there's no twist and the cable wants to rest at neutral.

 

[Telecaster]

Option 2 usually works best for me. I'll go 3rd, 4th, 5th, then reverse. I haven't tried 1st then reverse.

 

[1990ggsxnj]

Awesome info! I had some issues with my E-GS which eventually matured into popping out of gears. Had I known this I probably wouldn't have had to change it (or at least not as soon).

 

[iceman69510]

I don't know when it changed, but the spring used for the reverse brake cone was also made stronger at some point. When I rebuilt my tranny, the new spring was thicker material than the original.

I usually use the clutch in, other gear, then reverse method.

 

[JSchleim18]

I agree with Barnes as far as the techniques to get it in without grinding. I usually put it in 2nd then to reverse or I'll put it in reverse, and if it doesn't go in, I'll hold it there and bring the clutch pedal up until the shifter goes in gear.

 

[kaptainballistik]

Reverse was going in but could not be held in gear.

Got it apart, After all that grinding the Reverse Syncro looks in good condition ( As in it has intact eye teeth). The Reverse syncro appeared to have bugger all wear inside on the cone surface, But it did have some damage to one part of the surface .
The bit that looks like its threadded, It had 2 rows damaged that were about 2cm long ..And the Energiser relief was squared off a bit.

Hub was a little sloppy on the fork.

Im starting to think its a shift mechanisim issue...Can you get that all off without pulling the Box?

Anyway, the next step is to remove the shift fork , Undo the nut and check 5th ( After I find a willing acomplace to stick the thing into reverse whilst I hold in the Reverse syncro to check if its the shifting mec!)

Also, Will an EVO 3 Reverse syncro fit a E38 RS gearbox?
So to remove the rollpin, I assume I knock it inwards . My calibrated pinky finger seems to think its got enough clearance to do it......

 

[kaptainballistik]

The daily dim question...would GSR gallant ( 2wd) syncro's and shift forks fit?

 

[Barnes]

What you are looking at with the end case is only part of the action that occurs when you shift into reverse. When shifting into reverse the 5th/reverse slider moves outboard to apply the reverse cone brake. This being the syncro you are looking at. This only serves to stop the input shaft.

The second part of the mechanism is deeper inside the transmission. The 5th/reverse shift rail has a part that moves the reverse idler into position between the input shaft and 1st/2nd slider. Again, this all happens deeper in the transmission.

Having someone shifting into reverse could help you determine if it is a linkage issue. If the fork is moving out enough to fully engage the reverse brake, then I doubt it is linkage. I would bet in this case your reverse gear parts are terminally worn.

After that you'll have to remove both 5th gears, fork, 5th/reverse hub/slider, and viscous coupler, and ball detents. (I'm probably forgetting something small).

This will let you take the bearing plate, and intermediate case off. This is really the only way to see what is going on with the reverse gears directly.

This *can* be done in the car. I just sucks a bit.

 

[Barnes]

Quoting kaptainballistik:
The daily dim question...would GSR gallant ( 2wd) syncro's and shift forks fit?



The fork is not the problem unless it somehow physically prevents the 5th/reverse rail from moving enough.

You should be able to tell at this point if the fork is bent or not.

Oh, and yes, you can knock the roll pin out the way you mentioned.

 

[kaptainballistik]

looks at workshop manual and mutters something about frakkin 4wd rallycars......

Ok, That sounds like its check for anything obvious and if its bad then its pull the box out and give it a service time!

Last query till tomorrow..... Does anyone know what breakaway tourque the Viscus couppling should have, Should be able to make a Torque wrench adaptor for that....

Or if its obviously still operational ..Then just leave it?