gearbox troubles

Tensa Zangetsu · Postby **Tensa Zangetsu** » Sat Apr 06, 2013 11:23 am

Hey guys, my gearbox won't go into 5th and has trouble getting into reverse, if i grind it into 3rd it'll grind into 5th, and i have to be rolling to get into reverse, anyone got any ideas?

manga_blue · Postby **manga_blue** » Sat Apr 06, 2013 11:34 am

First make sure your clutch is disengaging properly. With the engine going, put it in first and slowly release the clutch. If it's hard to get into first when stationery or if it takes up when it's still way down near the floor then you have a clutch hydraulics problem. If the clutch is OK then just drive the car until you can't stand it any more and then put in another gearbox.

manga_blue · Postby **manga_blue** » Sat Apr 06, 2013 12:28 pm

Just to clarify, I think the probabilities are 80% for a clutch hydraulics problem, 15% for a gearbox problem and 5% for a clutch mechanical problem. That's good because the clutch hydraulic problem is by far the cheapest and easiest one to fix.

Tensa Zangetsu · Postby **Tensa Zangetsu** » Sat Apr 06, 2013 1:00 pm

Thanks, how would i go at troubleshooting the clutch hydraulics?

MrRevhead · Postby **MrRevhead** » Sat Apr 06, 2013 1:20 pm

The first thing you would want to check would be the clutch master cylinder. Check that there is enough fluid, the colour of the fluid and that there are no leaks. When the master cylinder seals leak, you normally see fluid up against the firewall, above the clutch pedal. Also do a visual check around the cylinder in the engine bay. They are rebuildable as well n.b if you are to replace it, the US master cylinders are different. So purchase one from a RHD (Aus, UK, Jap).

Then you might want to do a clutch bleed with DOT 3 brake fluid. Don't use DOT 4 as Mazda themselves recommend DOT 3 in the clutch hydraulics.

A more common problem on MX5s are the slave cylinders leaking. To check, crawl under the car and pull back the rubber sleeve on the slave cylinder. If fluid squirts out, you need to rebuild or replace the cylinder. The cheapest place to get a replacement is MX5 parts UK. They are only about 18 bucks + postage.

Best of luck!

Sent from my Galaxy Nexus using Tapatalk 2

Tensa Zangetsu · Postby **Tensa Zangetsu** » Sat Apr 06, 2013 2:31 pm

Cheers mate, and if that doesn't fix my problem, new gear box?

tbro · Postby **tbro** » Sat Apr 06, 2013 4:53 pm

Tensa Zangetsu wrote:Cheers mate, and if that doesn't fix my problem, new gear box?

Seized spigot bearing, but thats a gearbox out anyhow

manga_blue · Postby **manga_blue** » Sat Apr 06, 2013 5:53 pm

tbro wrote:
Tensa Zangetsu wrote:Cheers mate, and if that doesn't fix my problem, new gear box?

Seized spigot bearing, but thats a gearbox out anyhow

Probably a very good call, tbro, if the hydraulics are working.

Tensa Zangetsu · Postby **Tensa Zangetsu** » Sun Apr 07, 2013 8:46 am

But would it be easier/ cheaper to get a used gearbox and replace the one i got now or to take it out and get it fixed, (diy)

gslender · Postby **gslender** » Sun Apr 07, 2013 8:56 am

Depends on the price and condition of the used box. Speak to a local gearbox place first, and then talk to a 2nd hand supplier of mx5 parts for a quote on a used box.

noobee · Postby **noobee** » Sun Apr 07, 2013 9:28 am

Tensa Zangetsu wrote:But would it be easier/ cheaper to get a used gearbox and replace the one i got now or to take it out and get it fixed, (diy)

You seem to be in a rush to pull the gearbox out.Have you checked the master and slave cylinders yet?Last few I fixed (2x mx5's + 1 hyundai)cost $3 each cylinder.the seal in them is a standard size,your local clutch and brake shop buys them in boxes of 50.
Mick

Tensa Zangetsu · Postby **Tensa Zangetsu** » Sun Apr 07, 2013 9:55 am

noobee wrote:
Tensa Zangetsu wrote:But would it be easier/ cheaper to get a used gearbox and replace the one i got now or to take it out and get it fixed, (diy)

You seem to be in a rush to pull the gearbox out.Have you checked the master and slave cylinders yet?Last few I fixed (2x mx5's + 1 hyundai)cost $3 each cylinder.the seal in them is a standard size,your local clutch and brake shop buys them in boxes of 50.
Mick

not in any rush just like to do alot of research and weigh up my options before diving into it, better to be safe then sorry right lol, ill check the clutch seals first cause even if thats not the problem theyre probably due for a service on them

Tensa Zangetsu · Postby **Tensa Zangetsu** » Thu Apr 11, 2013 6:14 pm

I just checked the master and slave clutch cylinders amd there are no leaks, also how would the clutch stop the gearbox going into 5th/ reverse when all other gears work fine? I've done research and i think it could be a synchro.

MrRevhead · Postby **MrRevhead** » Thu Apr 11, 2013 6:30 pm

Assuming you have definitely ruled out the slave/master cylinders, changed brake fluid, checked the gearbox oil (or even try a change with VMX 80 and Nulon treatment), it might also be worth checking the lower nylon bushing on the gear stick and also turret oil. Even play around with the clutch grab adjustment behind the pedal to see if that makes anything a bit easier.

Just some quick, easy things to eliminate before concluding it is the box and going to the trouble of changing/rebuilding it.

Tensa Zangetsu · Postby **Tensa Zangetsu** » Thu Apr 11, 2013 7:00 pm

Yer, if i have to pull the gearbox apart i'll probably just say screw it lol iv had the car for years with this problem and i only wanted to fix it now cause i upgraded the engine, but i'll check everything. With the slave cylinder i moved that rubber gromit and there was no fluid inside, theres no leaks on the master, i'll change the fluid though just cause its most likely 14 years old.