Results 1 to 13 of 13

Thread: TH350 Problems

  1. #1
    Part of the furniture Justin_'s Avatar
    Join Date
    Jan 2012
    Location
    Port Macquarie
    Posts
    1,487

    Default TH350 Problems

    Th350
    5k stall
    Cooler
    Deep pan

    Firstly ive found the problem to only be in reverse and 1st.

    I've had troubles reversing up my driveway (15 degree angle) and when leaving in DRIVE it seems to hold out too long before it changes to 2nd.

    I topped up fluids as it was a little low but above minimum mark and it came good. The following weekend same problem. Levels are lower again. No signs or major leaks.
    Yesterday i jump in and reversed out like normal and same problem.

    Got under car to find fluid seeping out around the vacuum modulator line and slight ballooning of the hose...so i ran a new line from Vac Modulator to Carb.

    Test drive and all seemed great. Got home and
    popped the bonnet to find trans fluid had pissed out of the vac line all over the carb and manifold.

    Could it just be the modulator has shit itself or am i looking at internal problems??

    I bought the box 6yrs ago, reconditioned with receipts and a warranty and i know the work done was legitimate.

    In the 6yrs its copped a good flogging at drags and burnouts ect and it has served me well in that time.

    Any suggestions?
    Cheers

  2. #2
    Do you ever leave?
    Join Date
    Jul 2009
    Location
    Sometimes Melbourne
    Posts
    2,212

    Default

    I am assuming the vacuum line was connected to manifold ?
    Fluid all over carb and manifold can only get there from the dipstick and tube or do you mean it was inside the manifold ?

    If modulator has failed there should have been a decent white smoke cloud behind the car when you were driving.

    Replace the modulator and see what happens, you can put a vacuum pump on it and see if it holds to be sure.

  3. #3
    Part of the furniture Justin_'s Avatar
    Join Date
    Jan 2012
    Location
    Port Macquarie
    Posts
    1,487

    Default

    Vac line is connected to the full vac port on the carb push on nipple which is where the bulk of the fluid was found....mainly on the front half of engine drivers side.

    I have a new alloy deep pan on order along with a service kit. Ill add the modulator to the list.

    If by chance how would fluid coming out of the dipstick tube affect the problem of reverse and 1st not working properly?

  4. #4
    Do you ever leave?
    Join Date
    Jul 2009
    Location
    Sometimes Melbourne
    Posts
    2,212

    Default

    It wouldn't, just the oil on the carb and manifold.

    Never run a trans line to any ports on a carby, you'll have less problems if you live by this. Needs to go to a good source on the manifold.

    Reverse issue could be damaged direct clutch, pump or pressure related.
    High 1-2 shift may be modulator, may be related to vacuum port on the carb or a number of other things but do external things first.

    You really got to get that vacuum hose away from the carby.

  5. #5
    Part of the furniture Justin_'s Avatar
    Join Date
    Jan 2012
    Location
    Port Macquarie
    Posts
    1,487

    Default

    Just about to order a Modulator.
    From your experience which brand should i opt for....TCI or B&M? Prices are similar bur the TCI is cheaper.

    Also, should the mod vac line have its own vac port or is it ok to Tee into my brake booster line?

    The reason i ask is that the only vac port i have is on the NO#7 intake runner.
    If the modulator requires its own vac signal i would have drill and tap into the manifold at the rear of the plenum.
    Its a TP SP manifold.
    Thanks for your advice btw.

  6. #6
    Do you ever leave? EH179's Avatar
    Join Date
    Jan 2008
    Location
    Ipswich. QLD
    Posts
    3,462

    Default

    Have a think about a manual valve body and eliminate all those problems.

    I use to use a 2 port brass vacuum tree, for the brakes and trans.

  7. #7
    Part of the furniture
    Join Date
    May 2008
    Location
    Australia
    Posts
    1,009

    Default

    No need to buy a brand name modulator , those you list are just rebranded by them . Look up a local trans parts place like ATP motospecs
    Last edited by Gregaust; 08-01-2018 at 09:11 PM.

  8. #8
    Part of the furniture Justin_'s Avatar
    Join Date
    Jan 2012
    Location
    Port Macquarie
    Posts
    1,487

    Default

    Quote Originally Posted by EH179 View Post
    Have a think about a manual valve body and eliminate all those problems.

    I use to use a 2 port brass vacuum tree, for the brakes and trans.
    I have thought about it but i do like driving in D around town and local streets.....
    Im guessing converting to a manual valve body eliminates the modulator all together?

  9. #9
    Part of the furniture Justin_'s Avatar
    Join Date
    Jan 2012
    Location
    Port Macquarie
    Posts
    1,487

    Default

    Quote Originally Posted by Gregaust View Post
    No need to buy a brand name modulator , those you list are just rebranded by them . Look up a local trans parts place like ATP motospecs
    Badge engineering for sure mate. Theyre the only ones that pop up on ebay....if i can find one of same quality or better for $50 delivered im in

  10. #10
    Do you ever leave?
    Join Date
    Jul 2009
    Location
    Sometimes Melbourne
    Posts
    2,212

    Default

    Quote Originally Posted by Justin_ View Post
    Badge engineering for sure mate. Theyre the only ones that pop up on ebay....if i can find one of same quality or better for $50 delivered im in
    As greg mentioned ring a supplier or drop into your local trans shop and pick one up.

    Just so you know how much these things are, here's a supplier in the US and their listing.

    https://www.wittrans.com/parts?&type...R%20COMPONENTS

  11. #11
    Not the Kingswood! hq308's Avatar
    Join Date
    May 2010
    Location
    The Riff
    Posts
    1,989

    Default

    Quote Originally Posted by Justin_ View Post
    The reason i ask is that the only vac port i have is on the NO#7 intake runner.
    .
    I had the same issue with my Edelbrock manifold. I drilled and tapped the plenum for my booster and (in my case) ran the trans of the port on #8 runner

  12. #12
    E B
    E B is offline
    casual poster
    Join Date
    Feb 2015
    Location
    Sydney, Australia
    Posts
    364

    Default

    I'd say modulator is probably all that's wrong. If I forget to re-attach the vac line to the modulator, it does the same thing 1-2 shift really high.

  13. #13
    Part of the furniture Justin_'s Avatar
    Join Date
    Jan 2012
    Location
    Port Macquarie
    Posts
    1,487

    Default

    Thread update:

    Problem was the modulator in the end.
    Fitted a new one, a new service kit and a cast alloy deep pan.
    Found a bit of shit in the old pan when removing it...no metal but it looked like bits of coarse grit sandpaper?

    Shifts fine in all gears now..could probably do with a reco at some point.
    Last edited by Justin_; 07-03-2018 at 11:14 PM.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Th350 into vs ute
    By Tim304 in forum Driveline & Suspension
    Replies: 16
    Last Post: 24-01-2014, 08:55 PM
  2. th350 into wb
    By 308 tunna in forum Holden V8's
    Replies: 2
    Last Post: 26-11-2012, 11:38 AM
  3. th350
    By lifted white lux in forum Wanted (cars & items)
    Replies: 0
    Last Post: 06-11-2009, 10:38 PM
  4. th350
    By 323ci in forum Holden V8's
    Replies: 15
    Last Post: 24-02-2009, 11:14 PM
  5. th350
    By oldskool64 in forum Holden V8's
    Replies: 8
    Last Post: 16-05-2005, 05:29 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •