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Old 12-13-2005, 09:46 PM   #1
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Default 4th gear

My car doesn't seem to want to shift into 4th. I can be going anywhere from 20mph to 45 mph and it stays in 3rd revving at around 1400-2000 rpm. Somethmes i can be going 35 and it will shift and the gear seems different. In third i can blip the throttle and it will jump to 2200 rpm or more. When it is having one of its good moments and it shifts, going around 38 or so, i can blip it and throttle will not jump. It feels harder. Its like it is a stick.
The other day i was driving on a 50 mph street and was checking out my tranny and i could have sworn it totally skipped that "hard" gear and went on to OD or something.
I feel like i am killing my gas mileage not having a 4th gear goin 40 mph.
Is there any reason that 4th wouldn't enguage?

PS. sorry if its kinda worded wierd, its a complicated problem.
SRRY, forgot the year and trim 1990 eighty eight royale
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Old 12-13-2005, 09:57 PM   #2
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It would help if you had trim level and year in your sig.
I had similar problems with the 4T65e-HD in my GTP. I came up with possible problems it could be from others experience.
1. Splines on your 4th gear chewed off. You can tell this by dropping your tranny pan and checking for metal deposits on your magnet.
2. TPS not adjusted properly. There is a post in techinfo written by PontiacDad on this topic, I adjusted mine to 0.7v at Idle and 4.27v at WOT.
3. The problem of mine was a bad Transaxle Range Switch, mine didn't ever switch into OD because of this.
4. There could also be Torque Converter issues

The best way to figure it out is to take it to a tranny specialist. Otherwise if you have to know yourself, drop the pan and inspect the fluid. If it is nice and pink, doesn't have metal shavings and clutch material floating around in it it could be something simple. I wish you good luck because transmission troubles are never fun.
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Old 12-13-2005, 10:06 PM   #3
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Sry bout the lack of info..

So taking off the pan requires draining the fluid right? Im not sure that the gear is chipped because its not a hard shift. I'm going to have to see if i can get someone else to check the TPS. Dont you have to drill stuff for that?
Tranny problems ARE crap. At least its not like it wont shift out of first tho.
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Old 12-13-2005, 11:27 PM   #4
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Quote:
Originally Posted by ofnarcr4
Sry bout the lack of info..

So taking off the pan requires draining the fluid right? Im not sure that the gear is chipped because its not a hard shift. I'm going to have to see if i can get someone else to check the TPS. Dont you have to drill stuff for that?
Tranny problems ARE crap. At least its not like it wont shift out of first tho.
Yes when you remove the pan the fluid comes out as well. I would recommend also replacing the filter.

Yes to adjust the TPS voltage you have to drill out the mounting holes, but you do not have to do this to check the voltage.
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Old 12-14-2005, 12:10 AM   #5
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OD or the TC locking dosent occur untill 48mph.....
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Old 12-14-2005, 12:41 AM   #6
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Let'* not get confused here. The trans in the car in question is NOT a 4T60E. It'* a 4T60 or 440T4. It uses different controls and is not electronically controlled in ANY way.

The TPS will have no effect. Nor will OD lockup occur at a predictable vehicle speed as the 4T60E will.

Let'* dig deeper.
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Old 12-14-2005, 09:49 AM   #7
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Everything you have described with this trans is normal...

You will never see this car hit OD untill 48-50 MPH with very very light load... That would be with lockup...

In 3rd gear with the proper engine temps, the ECM will apply the TCC via the TCC Solenoid... This is the only electronic control in the transmission...

Now, there could be some other issues, such as the ECM will want the motor to be at 150F or so before it will apply the TCC in 3rd or 4th gear... You could be going 50 mph at around 2000 rpms without lockup, with lockup it should be 1450 or 1500 rpms... So the engine temps may be one issue...

Now there are also gear switches that the ECM uses so it will know what gear you are in that way the ECM will not apply the TCC in the wrong gear...meaning this is what keeps it from applying the TCC in 1st or 2nd gear... When you hit 3rd gear the ECM sees this and will look at engine operating temps, roadspeed and engine load and will then apply the TCC... If the 3rd gear switch was bad and the ECM didn't see the 3rd gear from the 3rd gear trans switch then you will never have the TCC apply in 3rd gear... But if you had a good 4th apply swith and the ECM sees the 4th apply switch the ECM could then safely apply the TCC if the right conditions are met..

So if the TCC applys at 38-40 with the engine at full operating temps then the trans is functioning as it should... There is no 4th gear at these speeds, its simply 3rd gear with the converter clutch locked to reduce fuel consumption which is also better for emissions and the environment... Once you get to 48-50 mph, you can actualy coast down and stay in OD through 46mph with TCC lock...

And as Willwren stated, keep in mind that this is a THM440-T4( 4T60 ) it is a fully hydraulic unit, the only electronic control the ECM has over it is the TCC apply...

You will want a scan tool to see the actuall engine temps, and the 2nd , 3rd and 4th gear switches... These are on off switches that are used by the ECM to control the TCC..

But again, I feel everything you are experincing is totally normal...

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Old 12-14-2005, 04:50 PM   #8
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From what you said i guess it could be normal. I am just wonderin though, why is that one gear so "hard"
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Old 12-14-2005, 05:23 PM   #9
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Cold shifts are always harder. It'* just a time of year thing. If you let the car warm up for an extended period of time, it should soften the shifts up.
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Old 12-14-2005, 06:34 PM   #10
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Quote:
Originally Posted by ofnarcr4
From what you said i guess it could be normal. I am just wonderin though, why is that one gear so "hard"
What do you mean by hard?

Hard as in its shifts hard? Or causes the engine to Lug?

3rd with TCC lock will have good pull, but the engine is closer to its peak torque as well... In OD at 50mph the engine is making good torque but its not at its peak...

And keep in mind that us 2.84 gear ratio guys are only running at 1400-1450 or so at 50 mph... And then on top of that you are driving a 3400 Lb car... If you have driven a stick, such as a small 4 cylinder you'll understand, it takes a lot to keep a 4 cylinder happy at 1400ish RPM'*, at that poing they are seriously lugging ands thats hard on the pistons and rings... With a V6, especially the larger more torquey V6'* you can spin them a bit slower than 1500.... when you get to V8'* I have seen some spin slower than any V6 we have here... Its about the firing continuity of the engine...

Either way I do not think you are having any real problems at the moment... Sounds as if the tranny is behaving pretty good... And remember, all THM440-T4'* were quirky at best .... I should know

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