Ooops.....

[jvbtte]

Last week, I was having trouble when I was driving aggressively with 3rd gear shifts grinding after the trans warmed up, shifts were above 5500rpm. T9 standard gear ratios, so I stupidly figured that I would adjust the clutch pedal, giving it more throw. NOT A GOOD IDEA!! After filling up at the local gas station, and answering all the usual questions, I slid into the driver seat, started her up, went to put her in gear when the clutch pedal went to the floor, resulting in a puddle of fluid under the bell housing on the pavement.

 

Another question, “is that thing fast?”

Reply, “its faster when not attached to a rope.”

 

I called Caterham USA and they said I over stroked the slave cylinder. This means extract the engine and trans from the car, separate the trans from the engine and replace the slave cylinder.

 

$#!t $$$$$

 

So, that is how I spent my Saturday and Sunday, getting intimate with my new yellow sled. Anyway, I was hoping this would help others not to do the same. Also I'm looking for advice, I would like to install a lightweight fly wheel. Caterham USA suggested

a Firdanza aluminum flywheel. The trans looks new, maybe a better 3rd gear synchro? I would like a close ratio trans, but I'm not sure I can afford one right now. Does any one know how much they cost and where I can buy one?, perhaps I could just install a close ratio gear set in my existing trans?

 

Carbon fiber drive shaft sounds good too. I would also like to install a Quaife LSD eventually. I'm not sure where to source any of these parts yet.

 

Any suggestions or advice would be greatly appreciated

[jlumba81]

This is what I got from Caterham USA when pricing out a Seven.

 

Transmissions:

Ford T-9 5-spd

36G003B: Gearbox – 5 Speed – Duratec

-This is the same T-9 transmission that has been used for years aside from a few minor changes. The nose piece is different to work with the Duratec bell housing/slave cylinder installation.

-Available through the Caterham Parts Department (Tony Mills: tonym@caterham.co.uk ph: 011.44.1322.625.801) and other sources.

-Retail: £1,000.00 + shipping

Ford T-9 5-spd, long 1st gear

SOP (special order product): Gearbox – 5 Speed – Duratec - Long 1st Gear

-Identical to the std. 5-spd above, but with a taller first gear ratio.

-Available through the Caterham Parts Department (Tony Mills: tonym@caterham.co.uk ph: 011.44.1322.625.801) and other sources.

-Retail: £1,145.00 + shipping

Caterham 6-spd

70000CSR: Gearbox – 6 speed – Duratec

-This transmission is similar to the 6-spd units we have been using for years. The nose piece is machined differently to fit the Duratec bell housing/clutch slave cylinder (the same as the CSR 6-spd).

-Available through the Caterham Parts Department (Tony Mills: tonym@caterham.co.uk ph: 011.44.1322.625.801).

-Retail: £2,450.00 + shipping

Caterham 6-spd sequential

67G003B(ST/CUT): Gearbox – 6 Speed – Sequential

-For use with Caterham Superlight R500. This transmission has straight cut gears which make it very loud, but incredibly strong.

-Available through the Caterham Parts Department (Tony Mills: tonym@caterham.co.uk ph: 011.44.1322.625.801).

-Retail: £5,124.25 + shipping

[11Budlite]

Jack - I'm not too sure how the Fidanza flywheel fits in a Caterham, but I know a few of the Birkin owners said that the ring gear was just a little bigger than the Ford piece and that they had to either elongate the starter mount holes to move the starter out, or machine the OD of the Fidanza ring gear a small amount. I think having a lighter flywheel is a nice mod on a Seven.

 

As far as the transmission, you can get a semi-close T9 transmission from John at Quantum Mechanics in Monroe, Ct. Those ratios aren't ideal for the weight of a Seven (in fact you might already have those in your car) but he might be able to build up something with a closer gearset. It might be worth a call to find out. I have one of his T9 conversions in my '64 MGB and it's been a great upgrade. Here's his site: http://www.quantumechanics.com/categories.php?op=newindex&catid=17

 

For my Birkin, I ended up rebuilding my T9 with a close ratio gearkit from BGH in England. Brian was great to deal with and I'm very happy with the results. I went with the E7 sporting close gearset with 2.75, 1.75, 1.26, 1.0, and .84 ratios. There is a minor machining mod that you have to do to the case that I was able to do at home with my drill press. Other than a small leak from the input shaft seal that I still have to fix, it's been a great upgrade. I did the upgrade in 2006 and I think I paid a little over $1000 for all the parts shipped to the states. http://www.bghgeartech.co.uk/html/5_speed.html

 

Here's a couple sites that I used to research the project.

 

Cherik rebuilt his gearbox with a BGH gearkit. He has a great step-by-step on the project: http://my.voyager.net/~quadrant19/Gearbox-upgrade.html

 

JohnCh has a Westfield with a BGH gearbox. His site has a nice gearing calculator: http://www.throttle-steer.com/

 

Phil (UK) also has BGH gearbox with a nice gear ratio calculator: http://www.our-nest.co.uk/Caterham/html_files/2004_cr_gearbox.htm

 

And if money's no object, there's always the Caterham 6-speed, Quaife, and others that I'm forgetting at the moment.

 

I would think that money would be better spent on other upgrades rather than a CF driveshaft, but that's just me...

[yellowss7]

http://www.blatchat.com/t.asp?ID=165734&pn=2&ps=15#1444716

 

Here's a link to the UK 7s site that has a caterham 6 speed for sale. 1100 pounds. plus a hefty shipping bill.

 

Tom

[Al N.]

The 6 speed is teh hotness, btw. Though at highway speeds it is buzzy...also, don't get thrown by the rattling at rest with clutch out (pedal not depressed). They all do that...

[yellowss7]

I have the Caterham 6 speed with the 3.62 rear and 13 inch wheels. I agree with Al, it is really slick. Nice short throws, great for keeping a free reving engine in the power band.

 

Not great for long highway jaunts as it's 1:1 in 6th, no overdrive. Probably not necessary with a torqy Duratec, but great for my high reving k series.

 

Tom

[jlumba81]

Yellowss7, what's the rev limit on your k series? I don't suppose anyone knows if they make a 6speed w/ an overdrive 6th gear?

[11Budlite]

"I don't suppose anyone knows if they make a 6speed w/ an overdrive 6th gear? " - I've never heard of a Caterham 6-speed with an o/d 6th gear. I think most owners will compensate for the direct 6th gear by using the 3.62 rear end with taller 15" tires.

 

If cost is no object, Quaife has a new 6-speed with an available o/d 6th gear that's supposed to be a direct replacement for the T9: http://www.quaife.co.uk/Quaife-6-speed-heavy-duty-in-line-RWD-sequential-gerbox They also have a less expensive (still not cheap!) 5-speed that looks to have decent ratios for a se7en with an o/d 5th gear: http://www.quaife.co.uk/Quaife-Universal-In-line-5-Speed-Rear-Wheel-Drive-H-Pattern-Synchro-Box

 

I rec'd a flyer from Taylor Race Eng in Texas that said they would have both of these available by the spring of 2009. This is from memory, so don't hold me to it. Here's their link: http://www.taylor-race.com/

[yellowss7]

Yellowss7, what's the rev limit on your k series? I don't suppose anyone knows if they make a 6speed w/ an overdrive 6th gear?

 

8000 rpm is the max rev limit on mine. Although some of the crazies in the UK that run big Hp have been known to have rev limits in the high 8's to low 9k range. I think those guys have to refresh the engine every 3000 miles.

 

Don't know of anyone running an overdrive 6th.

 

Tom

[JohnCh]

I put together a little gear comparison chart a while ago to quantify the difference between various options that might be helpful. It shows the speeds in gear, rpm after an upshift, and the rpm when cruising at 70 mph for the Caterham 6-speed, the BGH long 1st gear and two versions of the BGH Sporting close: one with the tightest 1st & 5th combo and the other with the shorter 1st and the tallest 5th. The speeds in gear assume a 7500rpm redline and 205/60-13 rear tires. I ended up keeping my 3.62 LSD diff and going with the BGH long 1st gearbox. The Duratec has such a broad torque curve that the 6-speed was pointless and although I would prefer the E7, it really requires a switch to a 3.92 to keep the gearing length reasonable. No complaints.

 

http://john15.web.officelive.com/Documents/gearcomparison.jpg

 

-John

[jvbtte]

Bruce, thank you for the link to BGH. I will try to get in contact with them. The E7 package looks real nice.

 

John, thank you for the gear ratio chart.

 

Al, I will get your heat shield back to you as soon as I get this thing back together and inspected, hopefully within the next few weeks.

 

I called Dick Brink earlier this week and he had some interesting input. He said that the T9 transmission should have a light weight gear oil in it to prevent grinding. He said he even heard of people using automatic trans fluid in their T9 transmissions. I am currently using Valveline synthetic 70/90. I would be curious to know what weight other members are using in their transmissions.

[JohnCh]

BGH recommends a GL4 semi-synthetic, followed by GL4 fully synthetic, but states to never use a GL4/5 blend. Their brand of choice is Comma, followed by Shell, Mobile, Silkolene, and Miller. I was unable to find any of those brand/weight combos in the US, so I went with Redline MT-90 which is their 75W90 GL4. It shifts great, but it is important to note that BGH specifically recommends against using that brand due to high wear seen in some customer gearboxes that used it. I've run Redline engine and gear oils in my cars for many years without any complaints, so I am not too concerned about this warning, but YMMV

 

-John

[Kitcat]

Ditto: Redline MT-90, 10K miles thus far and no problems.

[athens7]

BGH seems to be the only source that opposes using Redline transmission fluid. Many people on Blatchat use the MTL GL-4 (70W80). John Esposito (Quantum Mechanics) says the T-9 was designed for semi-syn, but it's not generally available in the USA. If one doesn't want to buy Comma oil from the UK (I want to use fluids I can reasonably expect to find in my area), John says the best choice is Redline MT-90 GL-4 (75W90). My car came with Castrol 80W90, and I found it to be fine when hot, but stiff and balky when cold. I much prefer the MT-90 that's in the box now. The one thing everyone seems to agree on is that GL-5 fluid is anathema to these transmissions, as it allows the synchros to wear out prematurely. Perhaps in colder climates the MTL would be good, but the original spec on the T-9 calls for 75W90 or equivalent, and perhaps using the lighter weight MTL contributes to the premature wear the folks at BGH worry about.

[Boxologist]

jack-

has the lightened flywheel arrived yet? before u install it, can u mark where it needs to be altered to properly fit the Zetec's starter and/or T9?

 

Also Caterham specifically mentions not to use anything but a GL4 in their manual.

[JohnCh]

Perhaps in colder climates the MTL would be good, but the original spec on the T-9 calls for 75W90 or equivalent, and perhaps using the lighter weight MTL contributes to the premature wear the folks at BGH worry about.

 

That was my guess as well, which is why I didn't worry about using Redline. The other thing that wasn't clear to me from my conversations with Chris at BGH is how many Redline filled gearboxes he has seen and how many of those actually had premature wear. Without that data it is hard to say if his guidance is based on a trend or merely a coincidence.

 

-John

[jvbtte]

Box:

I havent decided which flywheel to use yet. Dick Brink gave me some prices, but I havent received any spec on the flywheel yet. If anyone has any ideas as to which flywheel to go with, I could use the help because all of these decisions are a bit overwhelming as this is new to me, but that is a good idea, I will take measurements before I bolt it completely. The weather was so nice this weekend, I was tempted to replace the defective throw out bearing/slave cylinder, slap the thing back together again and take it apart again on a rainy day. I figure if I take the motor in and out enough times, I should be able to get it down to 4 hours, maybe less LOL.