Be4R Box Rebuild

[samthornton1990 23]

Now that the 16v is up and running I am going to be rebuilding the exisiting box with a better set of Ratios.

 

Just wanting to know what is required regarding fabrication, mounting of gears etc?

 

Everything I've read suggests that I can use my first 1st & 2nd gear shaft out of my 1.9 box, and then I was going to use 3,4,5 out of a gti6 box which should fit I assume?

 

Any pictures etc would be a great help

[mollisk 2 1 Cars]

The gears which you suggest will give you the closest ratios using standard parts. However, you will have to use BE1 /BE3 parts as a BE4R secondary shaft has a different spline profile. Also pay close attention to the tooth profile on the reverse gear train.

It may be best to build your complete 1.9 gearbox internals into the BE4R casing ( I assume you have a TU engine ? ) and substitute the 3/4/5 gears from a 6 speed box.

I would use new bearings and a new 1/2 synchro hub.

The Haynes manual is helpful

 

mollisk

[Miles 331 1 Cars]

Why do people have a thing about GTi6 3rd and 4th, these are well known to be the weakest gears in the entire Pug range and very often strip killing the box

 

The input shaft has machined gears (1 & 2) so these cannot be changed unless matched with the pinion shaft gears and as above the shaft dia can vary

[welshpug 1,626]

Because they are the closest 3-4 you can get without going for an aftermarket gearset

[samthornton1990 23]

The gears which you suggest will give you the closest ratios using standard parts. However, you will have to use BE1 /BE3 parts as a BE4R secondary shaft has a different spline profile. Also pay close attention to the tooth profile on the reverse gear train.

It may be best to build your complete 1.9 gearbox internals into the BE4R casing ( I assume you have a TU engine ? ) and substitute the 3/4/5 gears from a 6 speed box.

I would use new bearings and a new 1/2 synchro hub.

The Haynes manual is helpful

 

mollisk

 

 

Nice one! I have a complete 1.9 box at my diposal! Yes I've got a TU16v in.

 

Do I just use a BE3 bearing rebuild kit or would I have to use be4 parts?

 

Also is there any machining needed or does it all fit in?

[welshpug 1,626]

check the casing, I dont think a TU-BE box will have it but some of the higher torque applications have a smaller o.d bearing on the 5th gear end of the pinion shaft iirc

[mollisk 2 1 Cars]

Just to reiterate, f you do change the 1/2 synchro hub, double check the tooth profile on the hub. Re the GTi6 gearbox having weak gears, I have found that on stripping several of these boxes that the aluminum synchro cone on 3 rd gear is badly worn, but I haven't found one with damaged gears. I have built several boxes with these gears for rallying and not had any problems. As I have only found the worn synchros on 6 speed boxes, I speculated that it may be due to the longer promary / secondary shaft on theses boxes having less rigidity than the 5 speed boxes ??

Any TU BE boxes that I have built have used standard be1/3 bearings.

I now use a be1 group 'A' gearbox which is much better suited to rallying as compared to a "hybrid" gearbox with a 4.9:1 final drive.

 

mollisk

[welshpug 1,626]

if anything, the 6 speed units are stiffer than the 5 speed as the shafts are supported by three bearings each not two.

 

its the shallow tooth profile that causes issue, the reason you haven't seen it is that you have used functional units as donors, not grenaded ones murdered by a rally slick shod 2.0 n-a 205...

 

standard bearings for a be box are good enough, the ma can be uprated in certain areas however its casing flex that is its ultimate downfall, its torque limit is only 120 lbft! a good 1600 will be well over that, even a 1360!