• Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific Tech

Prothane Motor Mounts

  • Thread starter Thread starter palerider94
  • Start date Start date Mar 9, 2010
P

palerider94

Member
Feb 21, 2006
573
1
19
Mar 9, 2010
#1
  • Mar 9, 2010
  • #1
Was planning on putting new Poly Protahne motor mounts in my car to go with the new 347. I've read some post that say that they will cause a lot more vibration. Both most posts are attributing it trans poly mounts. Anyone just running solid or prothane motor mounts with oem trans mount? Curious on vibration levels. thanks
 
A

amorrow

New Member
Jul 15, 2005
99
0
0
St. Charles, IL
Mar 10, 2010
#2
  • Mar 10, 2010
  • #2
You will notice more vibration. I have poly Ron Morris mounts on my '65 with an OEM Toploader trans mount, and there certainly is more vibration, even with a camshaft milder than the one I had in the car when running stock engine mounts. That's not to say more vibration is a bad thing, though...it enhances the driving experience.
 

tx65coupe

Active Member
Nov 29, 1999
1,551
1
37
Mar 10, 2010
#3
  • Mar 10, 2010
  • #3
I have the RMP adjustable mounts that are poly. There is a little more vibration, but its not that much I'm not bothered by it at all.
 

66 Restomod

Member
Jan 2, 2007
203
0
16
Raleigh, NC
Mar 12, 2010
#4
  • Mar 12, 2010
  • #4
I went with the TCP mounts, and they are great (and stock style trans mount for T5).

Good thinking to install upgraded mounts with a 347. The TCP and RMP mounts won't pull apart like the stock style. I think the Prothane are also stock-style, but with urethane instead of rubber.

If you are doing a T5 too and might need some adjustability, I'd consider the TCP or RMP as well. I noticed about the same vibration with the TCP as I had with a broken stock-style mount.
 

rbohm

Founding Member
Apr 12, 2002
6,698
550
204
tucson,az
Mar 12, 2010
#5
  • Mar 12, 2010
  • #5
what you can do to eliminate some of the added vibration, if you find it objectionable with poly mounts, is to use a poly mount on the left side, and a stock mount on the right side since the right side mount is under compression and doesnt fail like a left side mount does.
 

DK832

New Member
Apr 11, 2006
291
0
0
Copenhagen, DK
Mar 13, 2010
#6
  • Mar 13, 2010
  • #6
I put poly motor and tranny mounts in my 351/69 and had a lot more vibration at certain rpm. Had the driveshaft balanced = helped with 50% of the 'new' vibration. Put back the rubber tranny mount and almost went back to std level vibration exept for ~2000rpm where there is a harmonic. The main result from the poly motor mounts was that I removed a slight wheel hop when burning out.
 

red302

Founding Member
Nov 21, 1998
881
0
17
Peru, IL
Mar 13, 2010
#7
  • Mar 13, 2010
  • #7
I used Prothane motor mounts in my '68 and have more vibration also. Mainly at about 2,000-2,500 rpm. It's not terrible, but you can definately feel it. Expecially if you are sitting at a stop and just rev the engine.
 
You must log in or register to reply here.

Similar threads

Motor mounts question
  • djj62478
  • Mar 18, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
15
Views
527
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Apr 13, 2026
nickyb
J
Bad Vibration
  • jefffletch47
  • Feb 12, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
7
Views
308
1996 - 2004 SN95 Mustang -General/Talk- Jun 2, 2026
dgrinnan
D
L
95 gt engine vibration
  • lenzgt
  • May 11, 2026
  • 1994 - 1995 Specific Tech
Replies
6
Views
234
1994 - 1995 Specific Tech May 26, 2026
lenzgt
L
S
Car shakes when taking off help???
  • STANKYstangs
  • May 10, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
12
Views
349
1996 - 2004 SN95 Mustang -General/Talk- May 27, 2026
LILCBRA
S
Drivetrain 8.8 Pinion and 302 rear main seal leaks after replacing. 93 5.0 with t-5
  • Steigy4827
  • Jun 23, 2025
  • Fox 5.0 Mustang Tech
Replies
10
Views
689
Fox 5.0 Mustang Tech Apr 1, 2026
Steigy4827
S
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?