If this gearbox was an auto on this cherokee, the valve body has a reverse pressure release valve, that even if you select reverse gear while driving forwards at speed, has a fail-safe which stops reverse gear from engaging.

If the box is a manual, even if its a reverse-syncroed gearbox and not a crash reverse, the reverse gear syncro would lock out at that speed regardless of how much force is applied to the gearstick.

P.S also note, on the automatic transmission on this vehicle (cherokee), it is electronically controlled, so that when the gearstick is selected in reverse, the computer reads the inibiter (sp) switch and does not allow the shift solenoids to activate reverse gear which is a secondry safety device, as well as the pressure release valve for first gear.

Perhaps you folks should reach the actual age of driving before you start talking about cars.........:doh:

I can't believe I even hit the reply button or I'm even on this forum anymore. What has happened? Why is the forum being overrun with children and childish arguements?

Are msn and myspace down?

The guys Cherokee was a Manual, he converted it himself from the Diesel model, as he prefered the Petrol engine, and I think he already had the gearbox spare, so cost him no extra money.

I'd love to know how pb32000 can chime in saying my post is bullshit, sure I wasn't there so maybe his gearbox being blended into zwarf on the motorway was a bit of an exaggeration, are you seriously telling me if you put your car into reverse whilst driving at any forward speed above 10, that you WOULDN'T do any damage at all? Unless of course you think the whole story is untrue, in that case open your eyes, this is the internet, majority of people lie anyway, hiding their true identity, lying about how smart they are by wiki'ing and googleing just so they can post something that looks technically true. When face to face, they wouldn't of been able to say anything, as they didn't know in the first place.

i remember they tried that once on mythbusters with a honda civic or something. they couldnt get it in reverse but i believe you

Quote from BlueFlame :

Unless of course you think the whole story is untrue, in that case open your eyes, this is the internet, majority of people lie anyway, hiding their true identity, lying about how smart they are by wiki'ing and googleing just so they can post something that looks technically true. When face to face, they wouldn't of been able to say anything, as they didn't know in the first place.

Your argument is "so what if i'm lieing, no-one else realised 'till they researched".

"I would of gotten away with it if it wasn't for you pesky kids!".

Quote from G!NhO :

i remember they tried that once on mythbusters with a honda civic or something. they couldnt get it in reverse but i believe you

It's what i was told by him, and he wasn't in his car the next morning for work, so i assume he was telling the truth

Quote from BlueFlame :

I'd love to know how pb32000 can chime in saying my post is bullshit, sure I wasn't there so maybe his gearbox being blended into zwarf on the motorway was a bit of an exaggeration, are you seriously telling me if you put your car into reverse whilst driving at any forward speed above 10, that you WOULDN'T do any damage at all? Unless of course you think the whole story is untrue, in that case open your eyes, this is the internet, majority of people lie anyway, hiding their true identity, lying about how smart they are by wiki'ing and googleing just so they can post something that looks technically true. When face to face, they wouldn't of been able to say anything, as they didn't know in the first place.

It's not that if you could put it into reverse at speed it wouldn't do damage, the fact is that you can't. You simply can't. Have a go yourself, it's not like anything will happen other than gear grinding.

We're not necessarily blaming you, he was probably telling complete crap. Maybe he hit a tree or something, and wanted to sound cool.

For me anyway, there was no need to research this. Not only does common sense dictate that trying to make everything in the gearbox spin backwards from 90MPH can't be good, I actually saw this on Mythbusters, Vroom Vroom, and Top Gear. All showed attempts to get 3 different cars into reverse at speed, all failed miserably. After a bit of research afterwards, I came to understand it. Mainly as my plan is to become an apprentice mechanic part time after school, to help fund college.

Maybe you should research it yourself before babbling about it here?

@ Blueflame. Its not your fault, its your freinds. He was bullshitting. In most, if not all manuals, it is pretty much impossible to put the car into reverse while going forward at such a high rate of speed. The gearbox would just lock out.

Quote from BlueFlame :

I'd love to know how pb32000 can chime in saying my post is bullshit, sure I wasn't there so maybe his gearbox being blended into zwarf on the motorway was a bit of an exaggeration, are you seriously telling me if you put your car into reverse whilst driving at any forward speed above 10, that you WOULDN'T do any damage at all?

What Nathan said.

Saying people aren't smart just by searching Google etc is a flawed argument. If what they find is correct, and they take it in, then they have learnt it, and are presumably therefore smarter.

Luckily I have enough experience building and driving cars to know you can't just bang a manual box in reverse at any sort of motorway speed, and thus didn't need to look it up.

Exactly. It's always worth asking someone who actually knows something about the topic rather than calling b.s.

I thought you might of knew your freind was b.s'ing anyway. Its common logic :/.

Cherokee's are good for money anyway . One of my job's is training as a gearbox technician, with my dad helping me (28 years experience) and we constantly get SUV's like cherokee's and M-classes (they are HORRID to work on) coming in. The only reason i know all that stuff about cherokee's gearboxe's and others, is from experience. Once you do it once with your bare hands, it clicks and never lets you forget .

Quote from Nathan_French_14 :

Exactly. It's always worth asking someone who actually knows something about the topic rather than calling b.s.

I thought you might of knew your freind was b.s'ing anyway. Its common logic :/.

Cherokee's are good for money anyway . One of my job's is training as a gearbox technician, with my dad helping me (28 years experience) and we constantly get SUV's like cherokee's and M-classes (they are HORRID to work on) coming in. The only reason i know all that stuff about cherokee's gearboxe's and others, is from experience. Once you do it once with your bare hands, it clicks and never lets you forget .

How is it common Logic? I've never experienced putting a box in Reverse at high speed, so how would I know if this does or doesn't happen? It's only common logic if you already KNOW that. I'm not crazy enough to try it. Others might be.

Oh btw, do you do ratio changes being a trainee? Or is that later on in the career?

Sorry to interrupt, but I'm getting my new car on Monday

And yes, it IS common sense you can't put a car in reverse at speed. I don't know particularly much about cars, but I did know this, and how did I know? Yes, common sense.

Congratulations on picking up the new car, hope you enjoy it.

@Blue, sorry for the late reply, but yes, i have changed gear ratios so far in my training process. I dont know whether im susposed to, but im working at my dads garage so im sure he's a little more leniant with me.