IS 250's manual tranny
08-02-06, 09:28 AM
#16
Originally Posted by gsrthomas
Well I have an 96 acura integra gs-r now. 150k miles original clutch, tranny has been phenomenal.
Lots of people (not saying you) that have tranny problems abuse their car and do not know how to drive a mt properly.
Lots of people (not saying you) that have tranny problems abuse their car and do not know how to drive a mt properly.
08-02-06, 08:44 PM
#17
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Toyota surely does not make a great gearbox, but saying Honda does is a bit foolish. If you haven't been inside a Getrag or a ZF, you haven't seen how to really do it right. My sole complaint with Getrag is their sheet metal roll pins for holding the shifter forks in place on the rods. Everything else is so incredibly well made, it's hard to find fault with them.
Of course, at $5,500 to replace a Supra's Getrag, it doesn't come cheap. I spent more on parts for rebuilding my Getrag 233 than a 300ZX owner pays for an entire gearbox.
Of course, at $5,500 to replace a Supra's Getrag, it doesn't come cheap. I spent more on parts for rebuilding my Getrag 233 than a 300ZX owner pays for an entire gearbox.
08-03-06, 05:55 AM
#18
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Honda manual trannies are problematic for everyone? Honda acknowledged their failure on the S2000 trannies?? There have been numerous recalls and TSBs regarding those and other Honda trannies???
What are you guys talking about?
"I heard it on an internet message board, so it has to be true."
What are you guys talking about?
"I heard it on an internet message board, so it has to be true."
08-03-06, 06:05 AM
#19
Originally Posted by ff_
Honda manual trannies are problematic for everyone? Honda acknowledged their failure on the S2000 trannies?? There have been numerous recalls and TSBs regarding those and other Honda trannies???
What are you guys talking about?
"I heard it on an internet message board, so it has to be true."
What are you guys talking about?
"I heard it on an internet message board, so it has to be true."
Regarding my statement about the S2000 tranny being problematic for "everyone" might have been overkill. I'm sure there were one or two that made it out of the factory without 2nd and 3rd gear problems. Actually, the initial test review done by Car and Driver mentioned that they had a problem with 2nd gear grinds in their test car..
08-03-06, 07:05 AM
#20
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The 2nd gear "grind" in the S2000 was the result of using an additional syncro, added since this gear change is the most "abusive". Especially when shifting at 9000 RPM. If you rev it up over 3500 RPM before shifting into second...the "grind" is not there.
The S2000 gearbox is known as one of the finest on the planet. Having owned one, I can see why it has that reputation.
The S2000 gearbox is known as one of the finest on the planet. Having owned one, I can see why it has that reputation.
08-03-06, 07:17 AM
#21
Originally Posted by ff_
The 2nd gear "grind" in the S2000 was the result of using an additional syncro, added since this gear change is the most "abusive". Especially when shifting at 9000 RPM. If you rev it up over 3500 RPM before shifting into second...the "grind" is not there.
The S2000 gearbox is known as one of the finest on the planet. Having owned one, I can see why it has that reputation.
The S2000 gearbox is known as one of the finest on the planet. Having owned one, I can see why it has that reputation.
Honda's TSB about the S2000 tranny stated that the issue was a problem with "stacked tolerances" in the shaft assembly, and the fix was to replace a few components (don't remember which). Of course, most people that got the repair performed didn't notice much or any improvement.
08-08-06, 01:20 PM
#23
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Originally Posted by 06LexIS
I spoke to one of the techs at the Lexus of Pleasanton when I was complaining about my tranny issues, we went for a test drive so he can hear my tranny noises from 1st-2nd and he told me that this manual tranny came from the Supra 6 speed, different gear ratios.
He also told me that the Toyota Tacoma TRD 6 SPD has the same tranny with different gear ratios/clutch assembly.
my .02 cents..
He also told me that the Toyota Tacoma TRD 6 SPD has the same tranny with different gear ratios/clutch assembly.
my .02 cents..
Last edited by Pittdawg; 08-08-06 at 01:55 PM.
10-16-06, 01:46 PM
#26
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It's the RA62. It has only one thing in common with the Getrag 233 found in the TT Supra. They both have 6 forward gears and one reverse gear. Nothing else is common or even similar. Your tech in Pleasanton is talking out his rear end. The Tacoma uses the RA60, not the RA62. They are practically identical inside according to the service manuals.
I've rebuilt two of the Getrags and have posted pics of the internals with a link in another thread. I looked up the RA62 in TIS, and I made certain there are no internal similarities. There are none. I could go into extensive detail, but suffice it to say the designs are only similar in gear count. Nothing else.
[EDIT] I looked a little deeper into the RA62 - it isn't even in the same class as the 233. It probably couldn't take the torque of the 2GR-FSE for long. It's far from a stellar design. Too complicated, too many choices for complexity over simplicity. The 233 is a very simple design, the RA62 looks like a typical Toyota design - OK for stock power, but not a brute by any means.[/EDIT]
I've rebuilt two of the Getrags and have posted pics of the internals with a link in another thread. I looked up the RA62 in TIS, and I made certain there are no internal similarities. There are none. I could go into extensive detail, but suffice it to say the designs are only similar in gear count. Nothing else.
[EDIT] I looked a little deeper into the RA62 - it isn't even in the same class as the 233. It probably couldn't take the torque of the 2GR-FSE for long. It's far from a stellar design. Too complicated, too many choices for complexity over simplicity. The 233 is a very simple design, the RA62 looks like a typical Toyota design - OK for stock power, but not a brute by any means.[/EDIT]
10-16-06, 03:22 PM
#27
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I wouldn't say that. I'd say I know a lot about the Getrag 233 in my Supra since I've rebuilt a couple of them. I've never played with the RA-60 or RA-62, but I did look at how they are put together in the New Car Features and their respective FSMs.
Whether the Tacoma shifter will work is anyone's guess. I mean it might be functional, but the position could be all wrong. It's very simple to modify a shifter, and the OEMs will do it in a heartbeat.
Whether the Tacoma shifter will work is anyone's guess. I mean it might be functional, but the position could be all wrong. It's very simple to modify a shifter, and the OEMs will do it in a heartbeat.
10-16-06, 03:47 PM
#28
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Damn, that's the answer I was afraid I would get, but thanks anyways. BTW, found some more info about the tranny:
New six-speed manual transmission for IS250
Lexus’ new IS250 and IS250 Sports models have the choice of new close-ratio six-speed manual or six-speed sequential automatic transmissions. IS200 was one of the first cars in its class at its Australian launch in 1999 with a six-speed transmission. IS250’s new Lexus RA62 manual transmission combines compact construction and high-quality shift feel.
It has triple-cone synchromesh on first, second and third gears to improve shift quality and gearbox durability.
A remote-controlled shift mechanism reduces gear **** vibration.
The shift mechanism includes four shift forks and a sliding-shaft-type shift shaft.
The RA62 transmission uses an output reduction system in the gear train rather than an input shaft reduction system, to reduce transmission size, weight and shift effort.
Safety features include a clutch-start system (the engine will not start unless the clutch pedal is depressed) and a release collar on the shift lever to prevent accidental engagement of reverse gear.
The RA62 transmission has ratios of first, 3.791; second, 2.275; third, 1.524; fourth, 1.185; fifth, 1.000; sixth, 0.786 and reverse, 3.466.
It is matched to a 3.583:1 final drive ratio.
IS250 manual has 261 square centimetres of clutch facing area, for optimum reliability.
The clutch pedal has a turnover mechanism to reduce pedal effort.
This found on the following website, and has lots of good infor bout the 250 in general:
http://www.japanesecarfans.com/news_...g/lexus/1.html
New six-speed manual transmission for IS250
Lexus’ new IS250 and IS250 Sports models have the choice of new close-ratio six-speed manual or six-speed sequential automatic transmissions. IS200 was one of the first cars in its class at its Australian launch in 1999 with a six-speed transmission. IS250’s new Lexus RA62 manual transmission combines compact construction and high-quality shift feel.
It has triple-cone synchromesh on first, second and third gears to improve shift quality and gearbox durability.
A remote-controlled shift mechanism reduces gear **** vibration.
The shift mechanism includes four shift forks and a sliding-shaft-type shift shaft.
The RA62 transmission uses an output reduction system in the gear train rather than an input shaft reduction system, to reduce transmission size, weight and shift effort.
Safety features include a clutch-start system (the engine will not start unless the clutch pedal is depressed) and a release collar on the shift lever to prevent accidental engagement of reverse gear.
The RA62 transmission has ratios of first, 3.791; second, 2.275; third, 1.524; fourth, 1.185; fifth, 1.000; sixth, 0.786 and reverse, 3.466.
It is matched to a 3.583:1 final drive ratio.
IS250 manual has 261 square centimetres of clutch facing area, for optimum reliability.
The clutch pedal has a turnover mechanism to reduce pedal effort.
This found on the following website, and has lots of good infor bout the 250 in general:
http://www.japanesecarfans.com/news_...g/lexus/1.html
10-16-06, 06:02 PM
#29
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That's almost word for word from the New Car Features book.
Here's the real issue - and why I think it's not a good design - the input and output shafts are not well supported. There is a front bearing for the input shaft that is mounted in the case. The rear end of the input shaft rides in bearings concentric with the output shaft. The output shaft is supported by a pair of tapered roller bearings. So there is no intermediate plate with bearing support to prevent shaft deflection under high loads.
While it is true the metallurgy does play an important part in the transmission's service life (particularly the hardening process), the bearings are undoubtedly the one thing resting between a good gearbox and a disaster. The farther apart they are, the more the shafts will deflect under torque, and the more the bearings will suffer. When the bearings suffer, death is not far down the road.
Also, the countershaft and the input shaft have synchros on them. This means the countershaft has free running gears and bearings on it. Not my first choice for gearbox design if power capacity is on the plate.
The Getrag 233's legendary status is because the countershaft is a single piece with fifth and sixth gears pressed on splines and bolted in place on the other side of the intermediate plate. So there are three bearings holding the countershaft - front, middle, and rear. The Output shaft is held in the front and the rear, not by two tapered rollers at the back, but by a tapered roller at the front of the shaft and a tapered roller at the rear. The input shaft is supported by a front bearing and a rear bearing riding on the nose of the output shaft, literally less than a millimeter away from the intermediate plate tapered roller bearing.
The Toyota design will work fine for stock power, but I wouldn't try to put 300 or 400 ft-lbs through it and expect it to be happy for long. I wouldn't even consider the 1000 ft-lbs that so many Getrag 233s have taken in stride.
Here's the real issue - and why I think it's not a good design - the input and output shafts are not well supported. There is a front bearing for the input shaft that is mounted in the case. The rear end of the input shaft rides in bearings concentric with the output shaft. The output shaft is supported by a pair of tapered roller bearings. So there is no intermediate plate with bearing support to prevent shaft deflection under high loads.
While it is true the metallurgy does play an important part in the transmission's service life (particularly the hardening process), the bearings are undoubtedly the one thing resting between a good gearbox and a disaster. The farther apart they are, the more the shafts will deflect under torque, and the more the bearings will suffer. When the bearings suffer, death is not far down the road.
Also, the countershaft and the input shaft have synchros on them. This means the countershaft has free running gears and bearings on it. Not my first choice for gearbox design if power capacity is on the plate.
The Getrag 233's legendary status is because the countershaft is a single piece with fifth and sixth gears pressed on splines and bolted in place on the other side of the intermediate plate. So there are three bearings holding the countershaft - front, middle, and rear. The Output shaft is held in the front and the rear, not by two tapered rollers at the back, but by a tapered roller at the front of the shaft and a tapered roller at the rear. The input shaft is supported by a front bearing and a rear bearing riding on the nose of the output shaft, literally less than a millimeter away from the intermediate plate tapered roller bearing.
The Toyota design will work fine for stock power, but I wouldn't try to put 300 or 400 ft-lbs through it and expect it to be happy for long. I wouldn't even consider the 1000 ft-lbs that so many Getrag 233s have taken in stride.
01-26-07, 01:33 PM
#30
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Lobuxracer: It appears you are the most knowledgeable concerning the IS 250 manual tranny, you state you looked into the internals of the Ra62 and it's nearly identical to the Ra60 used in the Tacoma (and Celica if I'm not mistaken). You think a short shifter for the Tacoma X-runner would work on our tranny's. Here's the link: http://www.performanceproducts.com/p...&vehicle=31454
i called bmracing today and they told me they have no plannings on making a short shifter for the is250..
