5th gear hard to engage

[Mightymetro]

Is there any adjustment on the 5th gear selection on a post 97 V8?

 

ive had the gearbox apart to reseal it and have now got super smooth changes 1st to 4th but going into 5th always feels tough and like it grinds in for a split second.  When I’m trying to get out of 5th it takes a bit of pull and not like any of the other gears.  I’ve looked in the manual but can only see a section on setting up the pre 1997 boxes with the translator 

[sailorbob]

Check that the 5th gear nut or secondary shaft nut hasn't worked loose.

[Mightymetro]

Hi, have had the back cover off and all looks ok 

[sailorbob]

Does double de-clutching on the upshift make any difference to the gear change? Also, what oil are you running in it?

[Mightymetro]

I tried double clutching but it doesn’t make it any easier

im using Titan race syn 5.  
 

its more that it just doesn’t feel an accurate change with the shifter position when you pull it over to 5th up position 

[sailorbob]

The oil may be the cause of the problem, Fuchs say it is not recommended for synchromesh transmissions. Also, its Viscosity Index is pretty low compared to TAF-X and Syntrans Transaxle 75W-90 (147 vs 210 and 195 respectively).

Are you sure there is no preload on the cables?

[Mightymetro]

Hi Sailerbob.  Sorry what do you mean by preload on the cables?  
 

is there any adjustment on the cables anywhere or are they a set length apart from how far the rose joint is screwed on ?

 

sorry if this sounds a bit simple 🤪

[cweeden]

Looks like you have some adjustment at each end of the cables. I'm not sure how to set these up correctly but expect good old trial and error might be a good starting point. 🙂 

 

[jonwat]

16 hours ago, Mightymetro said:

t going into 5th always feels tough and like it grinds in for a split second.  When I’m trying to get out of 5th it takes a bit of pull and not like any of the other gears.  

Careful, don't force it. Saw a V8 box where he'd been forcing it & the 5th gear brass selector fork had broken & fallen into the gears. Not a pretty sight. 

[sailorbob]

You need to adjust the length of the rod ends on the cables so that there is no preload on the cables when the transmission is in neutral and the gear lever is vertical (when viewed from behind) and it's spring has it in the 3rd / 4th gear plane position.

[ramjet]

Ok. Mine is a '94 S4, but I had issues with my adjustment. I spent some time mucking around with it and eventually got is it as close as I could to what the manual said. I must admit it is like night & day to shift now.

The adjustment on mine was at the 'box end and was to do with a linkage which anchors to the chassis. I was probably only out about 1.5mm in length, but that was enough to make fifth a pain.

Follow the manual and ask for help on here and eventually you will get it.

[DanR]

The book specifications gets you into the ball park and covers various inconsistencies between boxes pretty well. I found though I could achieve a more precise adjustment by firstly disconnecting the cables and links to operate the cross shaft and confirm each gear could be manually selected. It's quite a smooth and accurate system. (The change in the Renault Alpine works better than ours and demonstrates how good it can be. Being an outboard engine and gearbox like the 911 does that.) 

Once I knew the crossgate shaft can easily select each gear I measured the cross movement for each gate, with a vernier. Then I refitted the cables and adjusted the links to achieve the specs I'd measured earlier. My assistant would move the gearshifter and I used the vernier to fine tune the cross movement required for each of the gates. I also adjusted the limit block on the gear lever.

My S4 is the second gen of link bracketry while yours would be the fourth and final gen. It's that cross shaft movement though that the various adjustments set up for a sweet change.

Edited June 17, 2020 by DanR

[Mightymetro]

Thanks Dan, yes makes perfect sense and don’t know why I didn’t think to do the same.  Will let you know how I get on 👍🏻

[Mightymetro]

Right, a bit more on this.

 

So, ive  been under the car and had Sal changing gear so I can see the order of them And how they go in and the problem is definitely back end of the gearbox and not the cockpit gearstick.  I disconnected the cables and I can get all the gears fine except 5th and this moves side to side as easy as the others bt actually pushing the lever to get 5th requires much more force and the same to get it out so I’m now stuck on where to go.

before the strip and reseal there were no problems with 5th gear (assuming it’s my box that came back with the car) and I never undid any of the shaft nuts, just lifted the shafts out complete.  However, I have had the back selector cover off and stripped and wondered if there is a problem with how it’s built up.  I had to warm the cross shaft to get it out and wonder if it is maybe distorted somehow.  
 

might bite the bullet and order a new selector assembly to eliminate that which would then point to the selector fork / gear which I think might be beyond my skill set 

 

thoughts?

[Chillidoggy]

I know a man who’s very good with UN-1 boxes, he’s overhauled a lot of them, and just rebuilt mine with the Quaife ATB. Not often I recommend anyone, but I would in this case. I can give you his details if you want.

[Mightymetro]

Am I right in thinking that everything to do with 5th gear is inside the rear cover?  If I take the rear cover off again I guess if I push the 5HB selector the brass selector fork should just push and pull back and forth over the brass synchro? Am I right or simplifying it too much?

 

i think maybe I’m asking if I can change anything to do with 5th gear without taking the box out as I’ve got it dry as a bone and running

[sailorbob]

Yes, the 5th gears and corresponding selector shaft and fork are all inside the rear cover.

Just spitballing here, could the cross shaft operating finger have been fitted backwards?

[Mightymetro]

I’ll take another look but I think it’s offset and won’t engage in the other orientation

 

ill pop the back cover off again and take a peek and see how it looks 

[DanR]

2 hours ago, Mightymetro said:

Am I right in thinking that everything to do with 5th gear is inside the rear cover?  If I take the rear cover off again I guess if I push the 5HB selector the brass selector fork should just push and pull back and forth over the brass synchro? Am I right or simplifying it too much?

 

i think maybe I’m asking if I can change anything to do with 5th gear without taking the box out as I’ve got it dry as a bone and running

Yes. The crossshaft finger slots into each of the shift rods so, with all rods in neutral, I'd expect you should be able to move the 5th rod and fork back and forth. 5th is the gear set you can see when the cover is off. Look closely to see if something is jamming. Maybe that finger is catching on two rods. I've been thinking about grinding a slight chamfer on the finger edge next time I rebuild a box. (If your box is dry of oil and clean that can stiffen changes when testing the shifts.)

[Steve V8]

7 hours ago, Mightymetro said:

and I never undid any of the shaft nuts, just lifted the shafts out complete.

Presuming you have the same UN1 027 as I,

I didn't think it possible to separate the gear cases without first removing the shaft nuts and 5th drive and driven gears, to access the secondary shaft taper bearing retaining plate bolts. 

Have you reinstalled the 5th gear detent spring and ball bearing into the rear cover ?

 

[Mightymetro]

Sorted.  Thanks so much for everyone’s input on this.  I don’t know if it’s a bit embarrassing but after taking the back cover off and then seeing Steve’s picture and also reading a similar problem for SwindonAlan I realised that the washer was not fitted on the detent spring plug so therefore the spring was forcing the ball bearing too hard which was the cause of the stiffness.  
 

cant believe how good it feels now 🤪

[Barrykearley]

Yay - that’s ace