T5 Conversion vibration?

Discussion in 'Transmissions' started by BenRM, Mar 30, 2021.

  1. BenRM

    BenRM Member

    Joined:
    Aug 15, 2019
    Messages:
    11
    Likes Received:
    2
    Trophy Points:
    6
    Location:
    California
    Vehicle:
    1973 Ford Maverick
    Hey guys! I couldn't find much on this subject but I'm hoping someone here can help. I installed a T5 in my 73 Maverick and I have a vibration that starts around 45 and continues to worsen the faster I go (I haven't gone above 60 because of this vibration). I'm pretty sure it's the drive line angle causing this, but I can't raise the transmission any higher due to the height of the transmission tunnel. I know t5 conversions are relatively common, but is this an issue anyone else has had?
    To clarify, it vibrates above 45mph while accelerating in any gear, decelerating in any gear, and in neutral. Also I have 4.11 rear ratio with 25.5" tires so the driveshaft is spinning pretty fast even at these lower speeds.
     
  2. 71gold

    71gold Frank Cooper Supporting Member

    Joined:
    Apr 9, 2002
    Messages:
    25,741
    Likes Received:
    2,385
    Trophy Points:
    828
    Garage:
    1
    Location:
    MACON,GA.
    Vehicle:
    '73 Grabber
    if it does it in neutral, not the drive line. (you are sitting still?)
    sounds like wrong flywheel balance. I'm not a pedal person so I'm guessing.
     
  3. Hotrock

    Hotrock Rick, an MCCI Member Supporting Member

    Joined:
    Oct 27, 2012
    Messages:
    1,414
    Likes Received:
    644
    Trophy Points:
    303
    Garage:
    1
    Location:
    Munroe Falls, Ohio
    Vehicle:
    1972 Mercury Comet, 1997 Mustang Cobra
    From my experience, a vibration in neutral tends to eliminate anything from the transmission forward. Driveline angle issues tend to appear during acceleration and/or deceleration.

    Where did the driveshaft come from, is it original to the car and unmodified therefore a known quality unit? Are the 4:11s newly installed along with the T5 therefore an unknown? (When installing used components; never do more than one driveline modification at a time. Road test each changed used component separately.) Are wheels, tires and axles known quality components on the car prior to the T5 install?

    Is there any moan or drone to go along with the vibration?

    Please answer these questions to focus a vibration diagnosis.
     
  4. RMiller

    RMiller My name is Rick

    Joined:
    Dec 12, 2009
    Messages:
    3,738
    Likes Received:
    844
    Trophy Points:
    398
    Garage:
    1
    Location:
    Kennewick, WA
    Vehicle:
    1971 Maverick Grabber
    To add to the list of questions, is the engine original to the car and what flywheel did you use? If you do have the original engine and source the flywheel from a Fox that's the issue as suggested above.
     
  5. Powerband

    Powerband Member

    Joined:
    Nov 6, 2014
    Messages:
    330
    Likes Received:
    127
    Trophy Points:
    128
    Garage:
    1
    Location:
    NY's \H/
    Vehicle:
    ---- 1976 Comet --- 1974 Maverick- - '61 Comet T'Bolt Six ---- 'quite a few projects ...
    If you are getting the vibration when you are moving and in Neutral , the Pinion Angle likely is off. Shims are available to correct or minimize angle difference and driveline vibration. As in pic' shims can only minimize vibration tendency.

    [​IMG]

    https://www.summitracing.com/search/part-type/pinion-angle-shims?SortBy=BestKeywordMatch&SortOrder=Ascending&keyword=shims+rear+axle&N=part-type:pinion-angle-shims

    When installing the T5 in the '74, seemed easier cutting tunnel for T5 and retaining original driveline angle would be simpler than attempting to match pinion angle by using shims to minimize vibrations.

    [​IMG] . [​IMG] .

    . [​IMG] . [​IMG] .[​IMG]. [​IMG]

    [​IMG]



    hav efun
     
  6. BenRM

    BenRM Member

    Joined:
    Aug 15, 2019
    Messages:
    11
    Likes Received:
    2
    Trophy Points:
    6
    Location:
    California
    Vehicle:
    1973 Ford Maverick
    So many fast replies! Thank you for all the input!

    I know it's not the engine because it revs perfectly smooth in neutral while sitting still at any rpm, what I meant was that it vibrates in neutral at speeds above 45mph.

    Hotrock, the driveshaft is brand new and balanced from a local driveshaft company, the third member is also brand new (rebuilt), and the axles are brand new. The wheels and tires were driven on before and weren't causing any vibration. Also no droning sound, just a steady vibration that worsens with speed. This doesn't sound like a pinion angle issue?

    Powerband, that's what I'm afraid of but I'm trying to avoid modifying the tunnel if this is the case. Did you drive yours before cutting the tunnel for clearance, and did it have a similar vibration?
    I'm curious if anyone knows if it's possible to drop the engine about 1/2" to correct the drive line angle? (I highly prefer sticking to rubber mounts if possible)
    Also I'm not the best with measuring my driveline angle but according to a phone app I used (lol) it states that I'm 2.9 degrees off
     
  7. dyent

    dyent Member

    Joined:
    Jan 29, 2012
    Messages:
    921
    Likes Received:
    263
    Trophy Points:
    203
    Location:
    vancouver bc
    Vehicle:
    1973 Comet 2 dr., 302 w/AR aluminum heads, Toploader 4 spd, 9" Trac-Lok w/3.70
    Couple of other things, what about your T5? was it rebuilt, how where the input/output bearings, tailshaft bushing? Did you install a new pilot bearing, although this may not cause vibration, did you check the runout on bellhousing where the hole that input retainer sits, excessive runout will cause premature input bearing wear.......
    David
     
  8. Powerband

    Powerband Member

    Joined:
    Nov 6, 2014
    Messages:
    330
    Likes Received:
    127
    Trophy Points:
    128
    Garage:
    1
    Location:
    NY's \H/
    Vehicle:
    ---- 1976 Comet --- 1974 Maverick- - '61 Comet T'Bolt Six ---- 'quite a few projects ...
  9. RMiller

    RMiller My name is Rick

    Joined:
    Dec 12, 2009
    Messages:
    3,738
    Likes Received:
    844
    Trophy Points:
    398
    Garage:
    1
    Location:
    Kennewick, WA
    Vehicle:
    1971 Maverick Grabber
    Tremec has an app for the driveline angles and it is free. Will measure the angles and give you a green or red light.
     
  10. mercgt73

    mercgt73 Member

    Joined:
    Sep 6, 2003
    Messages:
    3,828
    Likes Received:
    346
    Trophy Points:
    223
    Location:
    Eastern Shore, Maryland
    Vehicle:
    1973 Comet GT (clone), 1974 Mustang II, 1980 Bobcat Wagon
  11. BenRM

    BenRM Member

    Joined:
    Aug 15, 2019
    Messages:
    11
    Likes Received:
    2
    Trophy Points:
    6
    Location:
    California
    Vehicle:
    1973 Ford Maverick
    The T5 is a brand new built unit rated to withstand 500hp to the wheels and a new pilot bearing was also used

    The tremec app is the one I used that states I'm 2.9 degrees off but while getting the engine angle and driveshaft angle are easy, the pinion angle is harder to find a good flat surface that I trust. It's also nearly impossible to measure it on flat ground because the car sits very low

    I have played with rear axle shims and first the 4 degree ones helped slightly then the 6 degree shims helped more but it just made the vibration less severe, it didn't eliminate it. (I measured with the shims installed and the app says it's off by 2.9 degrees still, which seems excessive but maybe it's right).
     
  12. Powerband

    Powerband Member

    Joined:
    Nov 6, 2014
    Messages:
    330
    Likes Received:
    127
    Trophy Points:
    128
    Garage:
    1
    Location:
    NY's \H/
    Vehicle:
    ---- 1976 Comet --- 1974 Maverick- - '61 Comet T'Bolt Six ---- 'quite a few projects ...
    T5 into the Maverick 'hits' - interferes at the front of tranny and firewall. To tip the tranny low enough to not hit at front requires tilting whole eng/tranny quite significantly down. The rear output shaft of tranny is much lower than original tranny output shaft and more significantly - output shaft centerline is at a severe angle rather than just being lower.

    Would like to know how T5 swap without altering tunnel was achieved. Previous mention of lowering entire eng/tranny seems viable but difficult alternative.

    hav e fun
     
    dyent likes this.
  13. BenRM

    BenRM Member

    Joined:
    Aug 15, 2019
    Messages:
    11
    Likes Received:
    2
    Trophy Points:
    6
    Location:
    California
    Vehicle:
    1973 Ford Maverick
    Well there's only enough room to safely lower the engine about 1/2” before the steering comes too close to the starter and oil pan, but if I can find engine mounts that would drop it this much I would buy them in a heartbeat

    Powerband, when you cut out the sheet metal to raise the transmission, did you weld in a new brace to make up for cutting the top of the tunnel brace?
     
  14. Powerband

    Powerband Member

    Joined:
    Nov 6, 2014
    Messages:
    330
    Likes Received:
    127
    Trophy Points:
    128
    Garage:
    1
    Location:
    NY's \H/
    Vehicle:
    ---- 1976 Comet --- 1974 Maverick- - '61 Comet T'Bolt Six ---- 'quite a few projects ...
    Anyone succeed with T5 install and NOT modifying tunnel and using corrective SHIMS ? - Sure seems easier ...


    did you weld in a new brace to make up for cutting the top of the tunnel brace?

    .. good question:


    Yes, cut the support brace / crossmember and welded a piece of C-Channel across, and more significantly modified the rear tranny support into a structural brace. It uses two OEM toploader support braces welded together with triangulated attachment struts for a bolt-in T5 crossmember.

    hav e fun

    [​IMG] . [​IMG]
    [​IMG] . [​IMG] . [​IMG]


    [​IMG] . [​IMG] . [​IMG] . [​IMG]


    [​IMG] . [​IMG] . [​IMG] . [​IMG]



    :ratrod:
     
    Last edited: Mar 31, 2021
    BenRM likes this.
  15. RMiller

    RMiller My name is Rick

    Joined:
    Dec 12, 2009
    Messages:
    3,738
    Likes Received:
    844
    Trophy Points:
    398
    Garage:
    1
    Location:
    Kennewick, WA
    Vehicle:
    1971 Maverick Grabber
    Never considered extending the reinforcement to the interior. I cut around the tunnel on mine and added an inch, totally removed the top of the brace and rebuilt it with 1/8 steel from Home Depot. This gave me all the clearance I needed for the TKO.

    [​IMG]
     
    BenRM likes this.

Share This Page