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olds bravada
6 Posts
Discussion Starter · #1 · (Edited)
Hi all,

Good news for me today is that my local transmission shop ran some diagnostics on my sloppy/soft shifting 4L60-E, and recommended simply upgrading the 2-4 Band Apply Servo to a "Corvette Servo" rather than getting into the valve body (or worse).

I'd read (at Sonnax) about a newer option, using the 4L70-E servo vs. the Corvette servo. This is an 'in-between' option that provides more area than the stock servo but supposedly a more refined 'feel'. Tranny shop guy says the Corvette servo can be a little harsh-shifting when the trans is cold. I live in Minnesota, so it can take a loooong time for the transmission to warm up sometimes.

Wondering if anybody has input on the Corvette servo in cold climates? Nasty or not too bad?

Has anybody tried the 4L70-E servo in a 4L60-E?

Finally, Alldata DIY tells me this is a 4.9 hour job (OUCH!!) on my 2003 Olds Bravada, mostly because you have to disassemble the exhaust system.

REALLY??? Anybody done this job without removing the exhaust? Here is the procedure from AlldataDIY:

2-4 Servo Removal Procedure

1.Raise the vehicle. Refer to Vehicle Lifting.
2.Support the transmission with a suitable jack.
3.Remove the transmission support.
4.Remove the front exhaust pipe assembly.
5.Remove the heat shield if equipped.
6.Carefully lower the transmission to gain access to the 2-4 Servo.
7.Install the J29714-A.
8.Tighten the bolt in order to compress the servo cover.
9.Remove the servo cover retaining ring.
10.Remove the J 29714-A.
11.Remove the servo cover and the O-ring seal. If the cover is hung up on the seal, use a pick (2) to pull and stretch the seal (1) out of the groove. Cut and remove the O-ring seal before removing the cover.
12.Remove the 2-4 servo from the transmission.

Greatly appreciate any and all thoughts/feedback/ideas.


2002 chevy trailblazer_ls
12 Posts
I have the Vette servo in my 2000 Snoma 4.3L, and not found the 1-2 upshift to
Be objectionable after cold starts in 10 deg. F weather.
Now below that temp I can't say...

Don't know about the exh. system on these vehicles.
Haven't looked closely enough at my son's TB to remember about this.
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