Be1 Box Jumping Out Of 5th

[philfingers 5]

My road rally car started jumping out of 5th this week

 

Mi16 engined, Gpn mounted, 4.44 cwp/1900 gearset BE1 box

 

Yesterday i changed the front suspension over so checked the engine mounts were fine, they are. Also no play in the rose jointed linkages (which have been proven over 10k miles), everything is nice and tight (it's all lockwired). Checked the oil too, drained and refilled (as I was removing drive shafts) and full 2 ltrs in there

 

Any suggestions as to where else to look

Edited August 23, 2009 by philfingers

[Tom Fenton 1,542]

Pull the end cover off the gearbox and check both nuts on the end of the 5th gear clusters are tight.

[philfingers 5]

Update:-

 

Yes Tom it was the nut on the end of the input shaft that was loose, tightened it up with high strength retainer for good measure and it's now fine

[Miles 331 1 Cars]

If thats works loose it's worth checking the spline as they can strip

[philfingers 5]

yes i did, as that had happened on the Mi box i used as a donor for this 6 years ago. luckily the spline was fine tho

[paulsupervts84 0]

i have to check that my does the same in my 205

[2-Pugs 57]

Just bringing up an old thread, as I have just started to get a similiar problem. Dropping out of fifth gear very occasionally under light throttle (cruising). A question- is there a specific method or technique used to lock the gearbox or prevent the shaft from turning when you are tightening the nut? I have read around elsewhere and there is some mention made of putting it into two gears at once, though I can't find out, or work out, how this is done.

 

Also I have a BE3 box not a BE1, though I assume is the same in this specific area, let me know if that assumption is incorrect

Edited February 14, 2017 by 2-Pugs

[welshpug 1,657]

its shown in the haynes manual, but basically drift out the roll pin on the selector shaft and push it into 5th gear by hand and select any other gear.

 

 

if you have an impact gun I find grabbing the gear with a gloved hand is enough.

[2-Pugs 57]

Ok, that's great. Many thanks WP. Annoyingly I don't have a Haynes manual to hand but I'll take a look and hopefully figure it out.

 

One other question, do I need to apply new threadlock to this nut, or adjust a locking tab, or am I just tightening it?

[welshpug 1,657]

just torque and stake as required, I don't think it needs threadlock.

[DamirGTI 342]

An piece of rag works suprisingly well for locking gears ! just stuff it in between the gear teeth and spin the shaft until it locks the gears

 

D

[Miles 331 1 Cars]

No threadlock, Just knock the sides in, New Nuts are around £4.50 and do them up twice as tight as whats stated, the figure is too low and that what causes the spline to round off

[Tom Fenton 1,542]

If the nut has been loose check the splines carefully on 5th gear synchro hub.

It's also worth using loctite on said splined connection and the end nut. They can rock on the stake.

[2-Pugs 57]

Gents. I am half way through this job at the moment and have a couple of questions.

 

I drained the gear oil which was shockingly low. I'd say there was only about half a litre in there. To be honest though I cant remember the last time I checked it. Come back to this in a moment.

 

Anyway I removed the end cover and I have two observations:

 

- neither of the nuts appear to be 'unstaked' Both seem secure in that sense

- second, the nuts appear not to have a regular six sided form but something different. So I'm not sure how I'm supposed to tighten them?

 

Going back to the oil level, I read in another thread that Jord mentioned his problem was caused by the oil level. So now I'm wondering if that is the cause of my problem and also how to proceed. Reassemble and hope for the best? Not sure how I can tighten these nuts either, and not sure they have even come loose, unless there is wear axially on the assembly that's increased the clearance.

 

Thoughts, comments?

 

 

[blandy 29]

12 sided socket will undo the nuts

[2-Pugs 57]

Thanks Blandy. Any idea what size? I have a cheapo socket set with me right now that only contains 6-sided sockets, so I'm going to have to buy or borrow the correct 12-sided sockets locally.

[DamirGTI 342]

You'll need 28mm 12 point socket for them shaft nuts .. best to buy it individually as it's an rare size which usually isn't included in the socket sets .

 

D

[welshpug 1,657]

your problem is more likely to be worn synchro ring or teeth.

 

draper 12 sided 1/2" drive socket is slim enough.

[2-Pugs 57]

Ok, sounds a logical conclusion WP in which case tightening the nuts isn't going to do much. I presume.

 

So I'm now wondering whether I should even bother trying seeing that I have to track down the 28mm socket. Just assume it's worn and needs further specific attention.

 

Got to drive from Holland to the UK on Sunday. Great timing eh.

[2-Pugs 57]

Well, got the 28mm socket this morning and un-staked the nut. Yeah, was loose. I reckon I was able to tighten it another 1/8 of a turn!! Will update once properly tested.

[welshpug 1,657]

did you check the synchro etc?

[2-Pugs 57]

Well, it all looked ok to my untrained eye, as did the splines. I'll see how it is when driving. Trip to Miles for repair is the backup plan.

[2-Pugs 57]

Well just completed 330 miles, almost all of it in 5th gear and had no problem with it coming out of gear at all so looks like that was the issue. No synchro problems or anything else apparent. A big thanks to all for your help :-)

 

Now just got to look at the cruising-speed occasional misfire that has developed. Oh the joys!