Where to find help when you want to change major units on your CF - engine, transmission, brakes etc. - or upgrade earlier models to later specifications.
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Raising the gearing on a 4 speed 2.3 Petrol

Post by Smiffy1968 » Tue Apr 10, 2018 2:40 pm
Joined: Sat Mar 24, 2018 8:46 am
Posts: 5
I have been considering options on raising the gearing on our cf350. 185R14 tyres on the twin rear axle. Considering putting 205 tyres on the back. Four of, they will touch walls at the road contact point. This would give me a 10% increase in speed to engine rpm. Can anybody see a proble with the tyre wall touching? I cannot personally but looking for opinions of the more experienced amongst us. Thanks, Paul

Re: Raising the gearing on a 4 speed 2.3 Petrol

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Post by Phil Bradshaw » Club admin » Tue Apr 10, 2018 4:42 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3543
Tyre wall contact on twin wheel hubs isn't necessarily a problem and can occur with 195R14 tyres on a laden CF350. I've not tried 205R14 though.
  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: Raising the gearing on a 4 speed 2.3 Petrol

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Post by VDUB384 » Club admin » Wed Apr 11, 2018 8:30 am
Joined: Wed Sep 12, 2012 9:01 am
Posts: 1323
I can't see to much of a problem but when twin wheel tyres rub against each other they get very warm, you also have to make sure they're commercial tyres if not your insurance company could void a claim if an accident happens. CF 350s are low geared for a reason and that's the weight they they have to get moving ,I know we're your coming from when you get your speed up you could do with another gear I run a 350 for 8 years and found the same I used to tow a classic caravan and if the gearing wasn't as low as it was there would have been a few hills that I wouldn't have been able to get up.
Dave
Whilst good maintainece is the best prevention"If its not broken don't fix it."
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Re: Raising the gearing on a 4 speed 2.3 Petrol

Post by Smiffy1968 » Thu Apr 26, 2018 9:18 pm
Joined: Sat Mar 24, 2018 8:46 am
Posts: 5
Thanks gents, your thoughts are greatly appreciated.

Re: Raising the gearing on a 4 speed 2.3 Petrol

Post by Smiffy1968 » Thu Apr 26, 2018 9:24 pm
Joined: Sat Mar 24, 2018 8:46 am
Posts: 5
I have wiggle room to pop in a 5 to 10mm spacer and i agree. The CF350 is a unit, ours is an Advantura full works camper. Whilst it will scream on a nice bit of road, it equally starts too lose it on an incline. Why i thought the tyre option of only 10% seemed easiest and best option. I feel that a 5 speed box would give me a 20% increase in 5th gear. I would be in and out of 4/5th like a yo yo.

Re: Raising the gearing on a 4 speed 2.3 Petrol

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Post by VDUB384 » Club admin » Fri Apr 27, 2018 9:39 am
Joined: Wed Sep 12, 2012 9:01 am
Posts: 1323
I ran a 350 Advantura for eight year and most of the time towing a classic caravan plus running on LPG Yes they do loose it on an incline but that's not a gearing problem it's more a weight to power problem. A five speed box will give you a higher top gear but you will still loose it on inclines one thing about the 350 with a four speed box it will climb steep hills I know this because I've been there.
Dave
Whilst good maintainece is the best prevention"If its not broken don't fix it."
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Re: Raising the gearing on a 4 speed 2.3 Petrol

Post by Smiffy1968 » Fri Apr 27, 2018 12:19 pm
Joined: Sat Mar 24, 2018 8:46 am
Posts: 5
Totally agree, it is a big old lump and the power issue. 5 speed is too much for a 350 imho. I reckon 10% with the tyre size increase is plenty. Yes i have noticed how it will pull up a hill. Good job for us as we heading to Cornwall twice this year.

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