Mushy B

So i had an rx7 2nd generation tranny that was just laying around so i brought it to school and decided to rebuild it. all of the casings are off and soon i'll be whipping out the dial indicator to start checking all the synchros and gears to see how they are. one thing i noticed is that the pilot bearing had litterally welded itself on to the input shaft of the tranny.... i had never seen or heard of this before, but it scares me because the tranny in my rx supposively has a bad pilot bearing and needs to be replaced, it's terrribly loud and sometimes i feel it may be a big resistor since my car has pretty poor accelteration, although it does misfire a lot so it's probably something in the engine. anywho, a friend of mine who works in a tranny rebuild shop tells me that rx7's have bad grounds throughout the car which i found out with my cd player, and that the pilot bearing is common to litterally welding itself onto the input shaft as a cause of these bad grounds. this is rather debatable to me, what do you guys think?

RotaryEvolution

iTrader: (30)

he's full of ****.

why would a pilot bearing cause a lack of ground issue? the transmission is bolted to the engine, i think that is plenty enough of a ground. the problem is there is only 1 major ground point at the starter from the battery and one to the chassis, both of those spots tend to get very greasy and oil soaked so adding more grounds to various spots is a good idea.

Mushy B

just out of curiosity.... why do you think the pilot bearing welded itself on?

turbine

iTrader: (1)

because it failed, overheated and friction welded its self to the shaft

sc0rp7

iTrader: (3)

^ ditto, about every pilot bearing i have replaced (minus 1) were starting to or had "wore out" and desintigraded... unfortunately as if they werent hard enough to remove normally, when all thats left is the outside case for the bearing, your pretty damn screwed, i just have become handy with a dremel and have been careful not to get the e-shaft...

- chris

torean

any pics of the rebuild?.....

turbine

iTrader: (1)

^ yep my pilot barring was not even damaged and it didnt want to come out. i was even useing a pilot barring puller. i ended up slicing it with a chisel there was a little damage to the eshaft but it was minimal
the biggest bitch on a rotary lol

88and93

You need to open the fluid feed hole up to .125 diameter. The stock hole is approximately half that size which is why this is a common failure mode.

RotaryEvolution

iTrader: (30)

wtf are you talking about?

Innovation

iTrader: (1)

^^^^ like he said, WTF are you talking about?

lovintha7

^^^^ Really. If you fed fluid onto the pilot bearing, you'd get it all over the clutch. That's not a good thing, since pilot bearings use a small amount of grease to stay lubricated.

Innovation

iTrader: (1)

Whats a fluid feed hole in the pilot bearing?

--MAstermind--

ok so in all honesty the fastest way to remove the throwout bearing while doing a clutch job is?

88and93

My apologies, he mentioned disassembling the transmission, and in my haste I thought he was talking about the input shaft bearing failing which is a common failure mode. Opening its feed hole solves the problem.

Mushy B

fastest way to remove the throwout bearing for meeee... would be whippin out the plasma torch and cutting the bitch out... but that would be only if you didn't care to destroy the bell housing and components inside it... otherwise just drop the whole tranny and take the bitch out

RotaryEvolution

iTrader: (30)

cutting the throwout bearing off? lol, re-read what you guys wrote..


easiest way i've found to remove the pilot bearing is take a propane torch and heat up the bearing a little and with a cheap, rentable kragen pilot bearing puller they always seem to come out without much hassle.

Mushy B

hell yeah! i used the oxy-accetalene torch we have at my school, it turned red hot and with a couple taps of a hammer it just fell off.

buttsjim

Strange thread. Everybody seems to be on a different wavelength, or something.