TomTurbo

Hello,

I've overhaulled my FRST like 4 years ago (140hp 230Nm torque (20% more than original)). I went the whole way ...
Now 4 years and 10000miles down the road my reconditioned gearbox started to make a bad noise. I put the gearbox out of the car, sent it out for inspection and ... bad news: the bearings started to wear out and that caused my gears tot run in to each other: my gearbox was ready for the junckyard...

I didn't want to spent so much money again on a reconitioning of the same gearbox and risking another fail 10000miles further down the road...

So i start looking on the internet for a sollution and found out that there are lots of people with the same question as me but seems like nobody nows exactly what to do.

So for all the guys out there with gearbox problems from a Fiesta RS Turbo or a Escort RS Turbo here are the answers:

First of all: The FRST and ERST use the same type of gearbox: BC5. It's a gearbox from the 80's and it seams like it isn't really strong enough for the 1.6 CVH turbo engine. Only difference is that ERST have 2 different versions of gearboxes (S1 and S2) and they have an LSD standard (i'm not 100% sure because i have FRST...

Annyway, when you start looking on the internet the gearbox they recommend is the IB5. What's that? It's the improved/ redesigned version of the older BC5. So it's used on later models (Example: Fiesta 3,5) . So why they don't fit on our RST's. Is this gearbox better? ... See pictures and comments below.
Remarque: Don't use the gearbox from a fiesta mk3,5 because they have hydraulic clutch bearings!

The one that will fit is the Escort MK5 (not sure)-MK6 1.8 TD gearbox (starter on the front). But, gear ratio's are different (shorter first gear and the rest longer (compared to FRST and ERST S1, ERST S2 hase different gear ratio's)). Fortunately there is a IB5 gearbox out there with the same gearratio's as the (F)RST's: the gearbox from the Escort Mk5 (not sure)-MK6 1.8 16v. Only prob: this gearbox has the starter ont the rear, so it won't fit our CVH engine.

Solution: (you see me comming): combine these 2 gearboxes: Use the gears and differential from the 1.8 16v and put this in the housing of the TD gearbox, check

Wow, that's it? ... nope sorry
The clutch will also be a problem, because all IB5 gearboxes use a bigger clutch bearing. This bigger bearing uses a flat surface to operate the spring and therefore it needs an edge on the spring (on the standard RST the clutch bearing is edged and the clutch spring is flat). See pictures below.
Therefore you need the Bearing and pressure plate (220mm) from the 1.8 16v (before 5/1997!!!). The clutch-plate is the same so doesn't mather...

Then ther's just one more thing :
The reverse light switch: this is also different on the IB5 gearbox. I recommend to take some wires and connect your original loom to the "new" switch". Or just drive without reverse light

Now fire it up and hit the road


These are the gearboxes i've used:

Escort MK6 1.8 TD (houssing only): 96WT-7F096 EA
Escort MK6 1.8 16V (gears and differntial only: 96WT-7F096 BA


Comparison (of the construction) between my original BC5 gerabox (gearbox code : 87T...) and the IB5 gearbox from escort MK6 1.8 16V. This comparisation is about the construction of the gearboxes. The construction is the same for all IB5-gearboxes (excl. the differences i've told). The purpose why i do this is to show if the IB5 is really a better gearbox?





Comparisation between BC5 (bottom) and IB5 gearbox (top)


Voila,

i hope i can help someone with this. Sorry for my enlish, but i'm not from England ...

Grtzzzzzzzzz

TomTurbo

Housing BC5





Housing IB5





Bearing 2nd shaft BC5





Bearing 2nd shaft IB5 <br/>Difference: more rollers compared to BC5 but diameter is the same!? <br/>I was a bit wondered, becouse on internet everyone tells they are bigger... but not in diameter!





Other housing BC5





Other housing IB5





Diff & housing 5th gear BC5





Diff & housing 5th gear IB5





Diff bearing BC5





Diff bearing IB5... same as BC5





Shafts & 5th gear BC5 (without gears)





Shafts & 5th gear IB5 (with gears)





Bearings first shaft BC5 (right) and IB5 (left) here allso no difference in diameter.





Bearing from previous picture (BC5)





Bearing from previous picture (IB5)





Other Bearing first shaft BC5





Other Bearing first shaft IB5 <br/>Same diameter





Original gearbox from my FRST (BC5)





Gearbox from Escort MK6 1.8 Turbo Diesel (IB5)





Gearbox from Escort MK6 1.8 16V (IB5)





Clutch bearing from IB5 gearbox





Aaaaaah, here are the differences between BC5 and IB5 bearings: thickness!!! (IB5 are thicker)





Aaaaaah, here are the differences between BC5 and IB5 bearings: thickness!!! (IB5 are thicker)





This bearing is also thicker on the IB5 gearbox (first shaft bearing)





This bearing is also thicker on the IB5 gearbox (first shaft bearing side engine))

Perfmr2

Im currently researching putting a IB5 box in my series 2, and this is a great help. Thank you

Rich87

Good thread I'm putting a box in my frst but I've got a zvh so I can use a rear starter box but wondering can you use the escort lsd in the box?

TomTurbo

Hey,

I think that it will slide in IF it has the same gearratio (i thought that Escort's had 2 different gearratio gearboxes)...

I'm not an expert in escorts... :-s

Grtz